TX winter wx thread: Spring-like pattern

[Johnny]

Yep, I'm now waiting till morning to make my decision on where to go, if anywhere at all. The last hour has me changing my mind and heading just north of the metroplex. Bags are packed and ready to go.

[A1A]

[TrekkerCC]

Yep, I'm now waiting till morning to make my decision on where to go, if anywhere at all. The last hour has me changing my mind and heading just north of the metroplex. Bags are packed and ready to go.

Even being in the metroplex should be sufficient. I'm actually thinking we might get some real good snows Thursday night and into Friday. I know North Texas snow events (winter weather events in general) tend to be well fickle (and ever changing), but I'm actually cautiously optimistic on this one. Of course, it going to make for one big gigantic travel mess on Friday and into the weekend.

[srainhoutx]

FXUS64 KFWD 060503 AAC
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1103 PM CST WED MAR 5 2008

.AVIATION...
PREVIOUS DISCUSSION THRU 00Z STILL OK. HOWEVER...TONIGHTS MODEL RUNS
GFS/NAM HAVE UPPED THE ANTE FOR SNOWFALL BEGIN THURSDAY LATE
AFTERNOON THROUGH FRIDAY MORNING. A RAIN/SNOW MIX SHOULD BEGIN TO
DEVELOP AROUND 21Z THEN CHANGE TO ALL SNOW THURSDAY EVENING AS THE
COLD UPPER TROUGH NEARS. FORCING/LIFT INDICATES THE BEST/HEAVIEST
SNOWFALL WILL HAPPEN IN THE 6-12Z TIMEFRAME FRIDAY...JUST BEYOND
THIS TAF CYCLE. 75

http://www.weather.gov/view/prodsByStat ... discussion

Your right about the travel mess. DFW looks interesting as well as DAL for that matter.

[cheezyWXguy]

I think a changeover maybe a little quicker than forecast at the moment, since my temp right now has already dropped to 37 degrees. This is gonna be a good one, and maybe even a school canceler, or at least delayer. According to that map, Id be getting 2-3 inches, and with a high in only the upper 30's, it will take longer to melt than it did on tuesday.

[Ed Mahmoud]

12Z WRF says 2 feet of snow at DFW today, per my PPV AccuWx MOS.

6 am temp (hour zero) was supposed to be 4.7ºC, actual 6 am temp was 5.6ºC, so WRF running a tad cooler than reality.

However, if all else is right, when two inches of liquid equivalent is falling, surface temp is below freezing, so over-simplifying and adding 1ºC gives surface temps just below 1ºC, plenty cold enough for snow, and at night, and with snowfall rates of 2 inches an hour, that would accumulate.


Note sure I actually trust the 12Z WRF.

The 12Z WRF is a full order of magnitude higher on snow than the 6Z GFS.

[Texas Snowman]

Anyone know what the single biggest snowfall in D/FW history is?

Tx Snowman

[AggieSpirit]

Not sure of the largest - but in Feb 2004 I had 7 inches from the Valentine storm in Arlington (close to Kennedale). That is the largest I remember.

If even a foot of snow were to verify --- that would just be --- well........SICK!

[Johnny]

I'm hitting the road here in an hour. My target area looks to be Sherman. I've sat here in Southeast, Texas for too darn long straining my eyes to see a flurry. This time I'm gonna go find it!!! lol

[wall_cloud]

you're chasing....snow?

[gboudx]

Email update from Jeff Lindner:

Snow Advisory in effect this afternoon and tonight for DFW metro area.



Heavy accumulating snows likely over N TX including DFW areas late this afternoon through tonight.



Discussion:



Late season winter storm will affect N TX the next 36 hours. Arctic cold front is through most of the region this morning and high temps. for the day have already been recorded. Temps. currently in the upper 30’s and low 40’s will fall throughout the day toward freezing by this evening. Upper trough along the New Mexico border will eject across TX late tonight and Friday with moisture being brought northward into the cold air mass. Already seeing light rains developing south of Waco moving northward as isentropic upglide begins ahead of upper trough.



Air column will be cold enough to support snow across the NW counties and Red River counties by early afternoon with rain mixing with snow DFW areas by mid afternoon. Rain/snow line will march southward and precip. will become all snow by early evening across the metro areas. Potential for meso scale snow bands to produce moderate to heavy snow with visibility down to ¼ to ½ of a mile at times and snowfall rates of .5 to 2” per hour under the heavy bands.



For now will go with widespread 1-2” along and N of I-20 and 3-6” Red River and NW counties with less than an inch across the southern counties. Snow will be wet and heavy…very good for making snow balls with temps. hovering around 30-32 degrees. May see even greater accumulations under snow bands…and this will need very close watch this evening as 8+” would not be out of the question under such heavy snow conditions especially over the NE counties.



Expect travel to become impacted by early evening as roads begin to slush over and elevated surface ice. Friday morning travel will be the worst given several hours below freezing overnight.



Will probably fire off another update this afternoon or evening to fine tune totals and overall threat…things always change when dealing with winter weather.

[Johnny]

wall_cloud, I live in Southeast, Texas...not Amarillo. Does it make a little more sense to you now?

[lrak]

Hey Johnny,

come down to Corpus before you leave, I've got beer

[wall_cloud]

wall_cloud, I live in Southeast, Texas...not Amarillo. Does it make a little more sense to you now?

no, I used to live in Corpus

[gboudx]

It makes perfect sense to me. Johnny lives in an area where snow events are very rare, and he wants to see some snow. So, he's going where there's forecasted to be snow so he can see some. Not any different from people who chase tornadoes; just a different type of weather.

Have fun Johnny and I hope you see some snow. *thumbsup*

[ColdFusion]

DFW NWS:

LIGHTNING SHOWS A BAND OF SCATTERED THUNDERSLEET OR THUNDERSNOW
MOVING EAST FROM THE ROLLING PLAINS.

Thundersnow!??! Bring it!

[AggieSpirit]

Moderate to Heavy rain with lightning and 38 degrees here at my Coppell office.

[Portastorm]

JB just posted a mid-morning update on his blog and he is still very bullish on 3- to 5-inch snows from Austin to the north and northeast with Dallas getting as much or more than earlier this week.

I am a JB fan and he's been dead on much of this winter ... but I'm really skeptical of snow falling as far south as Austin and his prediction. You folks in the DFW area and points east of there will probably see the white stuff but I doubt we will.

I'm not even lacing up my kicking shoes with this one and Lucy is still in her house!

[jasons2k]

I wish I could head up to DFW myself. This may be quite the storm when it's all said & done.

Here is Jeff Lindner's update for us in SE Texas:

Very active 36 hours expected over the state.

Heavy snows across much of N TX this afternoon and tonight.

Potential for snow across N 1/3rd of SE TX Friday morning

Threat of severe thunderstorms today.

Will break down by time periods as so much is going to be happening it will get out of hand real fast. Hope everyone is in a good mode as the time you get done with this your head will hurt as bad as mine and effectively a ? might be the better road to follow anyhow.

Today:

Surface low is currently forming over deep south TX ahead of deep upper trough driving SE through New Mexico. Already seeing showers on local radars and expect these to greatly increase in coverage and intensity late this morning and this afternoon. Arctic frontal boundary is moving southward and currently extends from near Lufkin to N of CLL to N of Del Rio. Influx of moisture ahead of deep S TX surface low and approaching disturbance over NE MX coupled with frontal lift spells on active afternoon. As capping erodes expect thunderstorms to increase between 100pm and 600pm across the region. Meager CAPE suggest limited instability however freezing levels will be falling as fringes of cold upper trough moves overhead so some large hail is possible along with gusty outflow winds. Low level shear supportive of supercells looks to be confined S of I-10 and really more so offshore.

Tonight:

Forecasting nightmare this period

Arctic cold front pushes off the upper TX coast mid evening with strong cold air advection onsetting and temps. plunging rapidly. As surface low moves to the NE of our region after midnight convective rains will end. However deep cold upper trough will still be west of the area and will move across Friday. After much model review and sounding review for both IAH and CLL there continues to still be the threat of winter precip. Friday morning through about noon along and north of a line from Liberty to The Woodlands to Hempstead. Heavy accumulating snows over N TX tonight within the post surface low wrap around shield and under the upper trough may dig far enough southward to produce snow over parts of SE TX. Forecast soundings at CLL are supportive of snow after 06Z (midnight) through about 18Z (noon) Friday…however there remains a 300-600m above freezing layer near the surface…which may support a rain/snow mix and little to no accumulation. For IAH soundings are a little warmer, but still cool over time and may support a rain/sleet/snow mix in the 300am-1000am period Friday morning. Moisture looks fairly meager on the soundings….and mainly trapped below about 800mb…suggesting what falls will be very light.

Next item to tackle is surface temps and any threat of accumulations. Feel freezing line will enter SE TX after midnight and ooze southward to about a Giddings to New Waverly to Coldsprings line. Whatever precip. and type that is falling at the time the surface temp. falls to freezing…some minor accumulations would be possible. Given the sounding profiles the main P-type in this region for this period would be sleet and snow. Main moisture slug will be carried east of the area by the time the air column is cold enough to support frozen precip…feel any accumulation will be light as long as no CSI banding develops and sinks southward from N TX. Still may see a dusting to ½ an inch of accumulation across Houston, Trinity, Polk, and San Jacinto counties mainly on elevated and grassy surfaces.

Cannot even begin to stress the uncertainty for this period given plethora of factors at play and as usual SE TX is always on the edge of the line between liquid and frozen and the forecast is never clear cut when dealing with winter precip…hopefully this will be the last time this winter at least for my sanity.

Friday:

Strong cold air advection in place all day with sub-freezing line in the morning across the N 1/3rd of the area. Thick low level clouds and strong N winds will result in little temp. recovery and expect a raw winter day with temps. averaging 20-30 degrees below average. Light precip. possibly mixed or frozen may be found during the morning hours. UKMET, CMC, and WRF models all show secondary vort max moving from NW TX toward E TX during the day Friday with a large patch of snow. GFS and NAM are not as aggressive with this feature. All models show 850mb 0C line and 540-546 DM thickness favorable for frozen precip. over SE TX Friday. Million dollar question is will there be enough moisture to squeeze out any precip. All models show dry slotting at 700mb with moisture trapped in the low level. Feel moisture will be lacking for anything of significance…but cannot rule out a few flurries.

***My concern Friday is that moisture is more and/or the secondary vort is able to squeeze out more QPF resulting in accumulating snows. While none of the available guidance shows this I have seen in C and SE TX before this time of year upstream vorts on the back side of deep upper troughs produce some snow. Honestly it is as much wait and see as any attempt at some kind of forecast.***

Friday night:

Models are wanting to clear skies fairly quickly and calm winds resulting in widespread freezing temps. Feel skies may be slower to clear given threat of secondary upstream vort max. With that said near freezing to freezing temps. are very much possible most areas Saturday morning with some areas into the upper 20’s where skies clear.

Weekend:

Sunny weather will return as deep upper trough moves east of the area. Cold air dome will modify Saturday as southerly winds return late in the day. Expect temps. to rebound to near 60 Saturday and into the lower 70’s on Sunday…or back to near normal.

Note: Daylight Savings Time begins Sunday at 200am. Clocks move forward one hour.

[Ed Mahmoud]

Rain changes to snow around Dallas, per WRF, ballpark 6 pm, give or take an hour.



Between 6 pm and 9 pm, well, this is just awesome. Of course, we must pray the WRF is correct... But three hour liquid equivalents between 0.5 and 1.0 inches (13 to 25 mm) coming down as snow!!!!!!!