Winter Forecast for North Texas

[CaptinCrunch]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
315 PM CST TUE DEC 7 2004

.DISCUSSION...
0-5 WAVE 500MB FORECAST EXPLAINS A LOT FOR NORTH TEXAS...POSITIVE
ANOMALITIES BUILDING OVER THE EASTERN PACIFIC AND WEST COAST WITH
NEGATIVE ANOMALITIES OVER THE EASTERN 1/2 OF THE COUNTRY.

A SERIES OF VIGOROUS SHORT WAVE TROUGHS WILL POP OVER THE DEVELOPING
WESTERN RIDGE AND INTO A LONG WAVE TROUGH OVER THE EASTERN 1/2 OF
THE COUNTRY DURING THE NEXT 7 DAYS. THIS WILL MAINTAIN A HIGHLY
AMPLIFIED PATTERN ACROSS THE CONUS FOR THIS FORECAST CYCLE... AND
GENERALLY DRY NORTHWEST FLOW FOR NORTH TEXAS.

NEXT CHANCE OF RAIN WILL BE WEDNESDAY NIGHT ACROSS THE SE 1/3 DUE TO
BRIEF ISENTROPIC RETURN FLOW THATS SHIFTS EAST OUT OF THE AREA ON
THURSDAY. THIS WILL BE FOLLOWED BY PACIFIC COLD FRONT THURSDAY
EVENING... AND ANOTHER ONE SUNDAY NIGHT. LOW LEVEL MOISTURE WILL BE
LACKING WITH THESE FRONTS... THUS THEY SHOULD ARRIVE DRY. THESE AIR
MASSES WILL BE OF PACIFIC ORIGIN... THUS NO SIGNIFICANT COLD WEATHER
IS EXPECTED.

This is an example of the NWS playing it cool with out looking foolish if things did not pan out. Expect a better look of next week by friday when the NWS should change their wording to a colder week ahead than first thought.

[gboudx]

So assuming they look at the same models, why would they even comment on the forecast that far out, when their forecast is very different from the models? Just say there is uncertainty and leave it at that.

[Portastorm]

Yeah it is pretty unusual for NWS forecasters to say much beyond Day 7 in their discussions unless something really dramatic looms, or if it's a slow weather day.



I'm sure we'll see more references to next week in the next 72 hours.

[CaptinCrunch]

that's just it they do look at the same models, but the GFS has been so BAD the past month with it's MRF or even the LRF over doing the cold air intrusions this far south that you have to forecast with a grain of salt.

The NWS is looking at all the models, GFS (MEX, MAV, and MET) EURO, NGM, ECMWF and so on, it's just that now they seem to be seeing the same thing which is the Eastern ridge is starting to break down and move eastward and with whats left of Typhoon Nanmadol moving into the NW around Alaska you create a funnel effect that pushes the colder air down thru the middle of the U.S and eastward. Plus you have no cut off low pulling warm moist air up from the Eastern Pacific or the GOM to work as a sliding block over the lower 48 which pushes the cold air off to the east or snuffs it out before it gets here. That's why the Panhandel got all the snow early Nov. the cut off low pulls down the cold air and funnels up the warm moist air and the moisture that wraps around the back side of the low into the colder air caused the snow. LUCKY THEM


In yesterdays AREA FORECAST DISCUSSION NWS FTW TX DEC 6

ANOTHER STRONG COLD FRONT WILL MOVE THROUGH NORTH TEXAS SUNDAY NIGHT
WITH BELOW NORMAL TEMPERATURES ACROSS THE REGION NEXT MONDAY. THIS
FRONT WILL BE OF NORTH PACIFIC ORIGIN AND CURRENTLY LOOKS SEASONABLY
COOL AND DRY.

LOOKING FAR AHEAD... OUR 16 DAY GFS IS SHOWING A POTENTIAL FOR
ARCTIC AIR TO INVADE THE SOUTHERN PLAINS AND NORTH TEXAS TWO WEEKS
FROM TODAY... ON MONDAY DEC 20. HOWEVER... THE UPPER FLOW PATTERN
REMAINS PROGRESSIVE AND THE ARCTIC AIR WILL MOVE EAST OF THE REGION
BY THE 22ND.

[AggieSpirit]

I wonder if this will happen --- this cold outbreak.

It seems like it has been several years since we have had a sustained period of temps no higher than the 30s.

In 1983, wasn't the temperature below freezing for extraordinary ammounts of consecutive days? I would like to see that happen again. Here is the other thing I want to see ---

Houston got 2 feet+ of snow in its region in the late 1800s once with 'Gulf effect' snow. Being the novice at weather that I am, what kind of pattern/setup would have to develop to have that happen again?

[CaptinCrunch]

NWS FTW TX FORECAST DISCUSSION...
DEC 8, 400 AM

WATER VAPOR LOOP SHOWS THE NEXT SHORTWAVE TROUGH RAPIDLY MOVING
THROUGH THE DESERT SW TOWARD NORTH TEXAS WITH A SHIELD OF HIGH
CLOUDS AHEAD OF IT. LOW/MID LEVEL CLOUD DECK DEVELOPING ACROSS
SOUTH TX WHERE ISENTROPIC ASCENT HAS ALREADY BEGUN. DESPITE STRONG
DYNAMIC FORCING LATER TODAY MOISTURE IS TOO LIMITED FOR CONVECTION.
HOWEVER OVER THE SE CWA...ISENTROPIC LIFT WILL MATERIALIZE AFTERNOON AND CREATE A LOW-MID LEVEL CLOUD DECK WITH A CHANCE OF LIGHT
RAIN THIS AFTERNOON AND EVENING. UPPER TROUGH CLEARS THE AREA AFTER
MIDNIGHT AND SKIES WILL CLEAR OUT FROM W TO E. MOS IS TIGHTLY
CLUSTERED ON TEMPS THROUGH TONIGHT AND SEE NO REASON TO DEVIATE.
HOWEVER...DOWNSLOPE WESTERLY WINDS MATERIALIZE THURSDAY AND WITH 850
TEMPS AROUND 10C HAVE FORECAST HIGHS 2-5 DEG WARMER THAN GUIDANCE.

AFOREMENTIONED SHORTWAVE TROUGH WILL MOVE INTO THE EASTERN US AND
BECOME INCREASINGLY BAROCLINIC AS IT PULLS ARCTIC AIR OUT OF CANADA
INTO THE DEEP SOUTH. RESULT WILL BE AN AMPLIFICATION OF THE UPPER
PATTERN WITH A RIDGE OVER THE WEST AND DEEP TROUGH OVER THE EAST. A
PIECE OF THIS COLD AIR WILL CLIP US FRIDAY AS A COLD FRONT MOVES
THROUGH AND NW WINDS INCREASE. THE SUBSIDENT NWLY FLOW ALOFT WILL
SPELL MAINLY SUNNY SKIES AND LARGE DIURNAL TEMPERATURE RANGES
THROUGH THE WEEKEND. HAVE BUMPED HIGH TEMPS UP SAT-SUN ABOVE MEX
MOS AS MODELS AGREE THAT 850 TEMPS WILL WARM TO 15C BY SUNDAY.

NEXT FRONT STILL SCHEDULED FOR LATE SUNDAY NIGHT AS A STRONG HIGH
PRESSURE OF PACIFIC ORIGIN BUILDS SE. CANADIAN/GFS ARE NOW SHOWING
A BRIEF OMEGA BLOCK ACROSS WESTERN CANADA WHICH WOULD HELP TAP A
LITTLE CANADIAN AIR AND BRING IT SOUTH EARLY NEXT WEEK. IN ANY
CASE...TEMPS WILL RETURN TO NEAR OR SLIGHTLY COOLER THAN NORMAL.
MOISTURE TOO LIMITED FOR MENTION OF PRECIP NEXT WEEK...BUT 700-850MB
RH FIELDS SUGGEST THERE MAY BE SOME MID LEVEL CLOUDS.

NWS NORMAN OK

ON SUNDAY... AT SOME POINT... THAT COLD FRONT IS DUE TO SWEEP SOUTH
THROUGH OKLAHOMA AND NORTH TEXAS... BRINGING EVEN COOLER
TEMPERATURES WITH IT. HIGHS SUNDAY WILL DEPEND HEAVILY ON WHAT TIME
THE FRONT PASSES THROUGH. THE LATEST MEDIUM-RANGE GUIDANCE SUGGESTS
A SOMEWHAT SLOWER FRONT THAN PREVIOUSLY ADVERTISED... AND HAVE MADE
SOME ADJUSTMENTS IN THAT DIRECTION. THE AIR INVOLVED WILL BE A
MIXTURE OF PACIFIC AIR AND THE EDGE OF THE POLAR AIRMASS... SO IT
WILL BE COOL... BUT NOT FRIGID.

LOWERED TEMPERATURES A BIT FOR MONDAY ONWARD AS IT APPEARS THAT THE
COOL HIGH TAKE A MORE DIRECT PATH INTO THE SOUTHERN PLAINS AND WILL
PROBABLY TAKE A FEW DAYS TO MODIFY.

DUE TO THE DRY NORTHWEST FLOW ALOFT... AND LACK OF MOISTURE RETURN
AT LOWER LEVELS... NO PRECIPITATION IS FORECAST - EXCEPT AS NOTED
ABOVE.

[Portastorm]

Did you see the last 2 GFS runs? Sheesh, nothing like waffling eh? The frustrating thing is most of the NWS guys seem to buy into the GFS and seldom mention looking at the Euro or the Canadian longer range models.

It's a joke. A bad one.

[vbhoutex]

I wonder if this will happen --- this cold outbreak.

It seems like it has been several years since we have had a sustained period of temps no higher than the 30s.

In 1983, wasn't the temperature below freezing for extraordinary ammounts of consecutive days? I would like to see that happen again. Here is the other thing I want to see ---

Houston got 2 feet+ of snow in its region in the late 1800s once with 'Gulf effect' snow. Being the novice at weather that I am, what kind of pattern/setup would have to develop to have that happen again?

I do believe that 1983 was the last time we had an extended period of "cold" or below freezing temps for an extended period of time(more than 24 hours is a long time here in the deep South).

I am not positive of the set up that happened with the snow dump of 20"+ here in the late 1800's, but I'll give it my amatuer try with a request to the Pros to correct or further explain. Basically we would need to have an Arctic blast in place with this cold air through all levels of the atmosphere. Then a shortwave or cut-off low coming from our W or SW pumping copious amounts of moisture up and into/over the cold air already in place should do the trick. It would have to track to our(Houston's)South or right over us for some of this to occur. IE we would need to be on the "dirty"side of the low like with a TC.

[Portastorm]

I wonder if this will happen --- this cold outbreak.

It seems like it has been several years since we have had a sustained period of temps no higher than the 30s.

In 1983, wasn't the temperature below freezing for extraordinary ammounts of consecutive days? I would like to see that happen again. Here is the other thing I want to see ---

Houston got 2 feet+ of snow in its region in the late 1800s once with 'Gulf effect' snow. Being the novice at weather that I am, what kind of pattern/setup would have to develop to have that happen again?

I do believe that 1983 was the last time we had an extended period of "cold" or below freezing temps for an extended period of time(more than 24 hours is a long time here in the deep South).

I am not positive of the set up that happened with the snow dump of 20"+ here in the late 1800's, but I'll give it my amatuer try with a request to the Pros to correct or further explain. Basically we would need to have an Arctic blast in place with this cold air through all levels of the atmosphere. Then a shortwave or cut-off low coming from our W or SW pumping copious amounts of moisture up and into/over the cold air already in place should do the trick. It would have to track to our(Houston's)South or right over us for some of this to occur. IE we would need to be on the "dirty"side of the low like with a TC.

Yes, this sounds quite likely. In fact, I believe this was the atmospheric set-up in 1985 when San Antonio got a foot of snow.

[CaptinCrunch]

MODELS ARE IN GOOD AGREEMENT WITH THE NEXT FRONT EXPECTED TO ARRIVE
ON SUNDAY NIGHT. PACIFIC HIGH PRESSURE WILL STRENGTHEN IN WESTERN
CANADA WHERE STRONG HEIGHT RISES ARE PROGGED. UPPER PATTERN WILL BE
FAVORABLE FOR SOME CANADIAN AIR TO BE PULLED SOUTH. AN INCREASE IN
CLOUDS IS EXPECTED AFTER FROPA DUE TO WEAK ISENTROPIC LIFT BUT HAVE
KEPT FORECAST DRY WITH THE BEST MOISTURE STAYING TO THE WEST.
SLIGHTLY COOLER THAN NORMAL TEMPS EXPECTED NEXT WEEK AS THE HIGH
TAKES UP RESIDENCE OVER THE STATE FOR A COUPLE DAYS.

LONG RANGE MODELS ARE INDICATING A RETURN TO A WET PATTERN A WEEK
FROM TODAY AS A STRONG SHORTWAVE DROPS SOUTH AND CUTS OFF OVER THE 4
CORNERS. AT THE SAME TIME TEMPERATURES WILL BE PRETTY CHILLY...AND
A COLD RAIN LOOKS LIKE A GOOD BET.

[gboudx]

Just for fun I was checking Accuweather this morning. They have rain and/or ice forecasted for next weekend. I hate ice.

[gboudx]

AREA FORECAST DISCUSSION...UPDATED FOR AVIATION DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
505 AM CST FRI DEC 10 2004

.DISCUSSION...
400 AM
SURGE OF COLDER AIR AT 850 IS NOW MOVING THROUGH THE REGION WITH
SURFACE WINDS INCREASING AND MODEST PRESSURE RISES OCCURRING TO OUR
NW. DIURNAL MIXING WILL BRING STRONGER WINDS TO THE SURFACE AND
EXPECT 15-25 MPH THIS AFTERNOON ACROSS THE NE HALF OF THE CWA...WITH
SLIGHTLY LOWER SPEEDS ACROSS THE SW HALF. TODAY WILL BE A LITTLE
COOLER DUE TO THE COLD ADVECTION...BUT GENERALLY CLEAR SKIES WITH
COOL NIGHTS AND WARM DAYS WILL CONTINUE THROUGH SUNDAY.

AMPLIFIED UPPER LEVEL PATTERN WILL SEND A HIGH OF PACIFIC ORIGIN
SOUTHWARD EARLY NEXT WEEK. HIGH PRESSURE WILL STRENGTHEN TO 1045 MB
IN WESTERN CANADA THIS WEEKEND BENEATH UPPER SHORTWAVE RIDGING...AND
WILL ALSO TAP INTO SOME COLDER AIR IN CANADA. FRONT SHOULD ARRIVE
RAIN FREE SUNDAY EVENING. HIGH PRESSURE WILL SLOWLY BUILD IN...A
SIGN OF AT LEAST 2 OR 3 DAYS OF COOL TEMPS. GUIDANCE IS REASONABLE
ON FORECASTING TEMPS SLIGHTLY COOLER THAN NORMAL MON-THU.

FORECAST GETS MORE UNCERTAIN BY THURSDAY AS GLOBAL MODELS BEGIN TO
DIVERGE ON THE FATE OF THE NEXT SHORTWAVE DROPPING SOUTH ALONG THE
PACIFIC COAST. CANADIAN/GFS CUT THE ENERGY OFF INTO AN UPPER LOW
AND RETROGRADE IT WEST OUT INTO THE PACIFIC TO FORM AN IMPRESSIVE
REX BLOCK. UKMET/ECMWF/DGEX KEEP THE UPPER LOW OVER THE SW US WHICH
SUGGESTS A CHANCE OF OVERRUNNING RAIN. BOTH SCENARIOS AGREE THAT
COLD AIR WILL CONTINUE TO MOVE SOUTH INTO THE PLAINS AND HAVE
CONTINUED A COOLER THAN CLIMO FORECAST IN DAYS 6-7. ALSO THERE IS
AGREEMENT ON A STRONG SUBTROPICAL JET OVERHEAD SO A MOSTLY CLOUDY
FORECAST LOOKS GOOD. THE RAIN FORECAST IS OPEN FOR DEBATE BUT WILL
CONTINUE THE SLIGHT CHANCES OF RAIN ON THURSDAY TO AVOID FLIP
FLOPPING THE FORECAST BEFORE THE MODELS REACH A CONSENSUS. TR/92

[CaptinCrunch]

The last part say's it all......

FORECAST GETS MORE UNCERTAIN BY THURSDAY AS GLOBAL MODELS BEGIN TO DIVERGE ON THE FATE OF THE NEXT SHORTWAVE DROPPING SOUTH ALONG THE PACIFIC COAST.

CANADIAN/GFS CUT THE ENERGY OFF INTO AN UPPER LOW AND RETROGRADE IT WEST OUT INTO THE PACIFIC TO
FORM AN IMPRESSIVE REX BLOCK.

UKMET/ECMWF/DGEX KEEP THE UPPER LOW OVER THE SW US WHICH
SUGGESTS A CHANCE OF OVERRUNNING RAIN.

BOTH SCENARIOS AGREE THAT COLD AIR WILL CONTINUE TO MOVE SOUTH INTO THE PLAINS AND HAVE CONTINUED A COOLER THAN CLIMO FORECAST IN DAYS 6-7.

ALSO THERE IS AGREEMENT ON A STRONG SUBTROPICAL JET OVERHEAD SO A MOSTLY CLOUDY FORECAST LOOKS GOOD. THE RAIN FORECAST IS OPEN FOR DEBATE BUT WILL CONTINUE THE SLIGHT CHANCES OF RAIN ON THURSDAY TO AVOID FLIP FLOPPING THE FORECAST BEFORE THE MODELS REACH A CONSENSUS.

[aggiecutter]

The first front early next week should send temps 8-10 degrees below normal for a few days in extreme NE Texas early next week. Local mets. are calling for highs in the mid to upper 40's and lows in the mid-20's for the Texarkana area on Monday and Tuesday. I pretty much agree with their forcast.

The front late next week into the weekend will more than likely be somewhat stronger than the one earlier in the week. The cold be will be more expansive and long lived. It's possible that an overrunning situation could develop, so areas of Northern and Eastern Texas need to be on the outlook for a possible icing situation. I'm not sure about this, but this is something that needs to be watched as this type of pattern has favored such events in the past.

Christmas week is going to be very cold. Whether there is any wintry precip remains to be seen. This mornings long range EURO and GFS Ensembles are in very good agreement on a pattern that is a classic setup for wintry events over Texas and much of the southern US. A Rex block with an undercutting southern stream means things will get very interesting Christmas week in the southern plains. It should be an interesting couple of weeks starting the end of next week.

[sertorius]

Aggiecutter:
I just posted on this in my "crazy question" scenario-I totally agree with you!! However, local mets in KC are calling for temps in the mid to upper 40s for the 24th and 25th with no precip-I'll by the no precip as an idea (I think the details may sort out differently later on-STJ looks to get going and the models have had trouble with this all Fall) but the temps in the 40's I don't get if all you have to guide you trend wise is the GFS?? We shall see!!

[cctxhurricanewatcher]

The first front early next week should send temps 8-10 degrees below normal for a few days in extreme NE Texas early next week. Local mets. are calling for highs in the mid to upper 40's and lows in the mid-20's for the Texarkana area on Monday and Tuesday. I pretty much agree with their forcast.

The front late next week into the weekend will more than likely be somewhat stronger than the one earlier in the week. The cold be will be more expansive and long lived. It's possible that an overrunning situation could develop, so areas of Northern and Eastern Texas need to be on the outlook for a possible icing situation. I'm not sure about this, but this is something that needs to be watched as this type of pattern has favored such events in the past.

Christmas week is going to be very cold. Whether there is any wintry precip remains to be seen. This mornings long range EURO and GFS Ensembles are in very good agreement on a pattern that is a classic setup for wintry events over Texas and much of the southern US. A Rex block with an undercutting southern stream means things will get very interesting Christmas week in the southern plains. It should be an interesting couple of weeks starting the end of next week.

Bastardi, in his morning update ,sounds like we may have a mess here in Texas come Christmas week!

[vbhoutex]

Everyone I read, converse with, trust, etc. is buying into this being as at a very minimum one of the most interesting and possibly cold and ? precip for the Southern plains, deep south, even possiblyinto Florida during Christmas week. The models are all still trending that way too. There is only one person I haven't talked with about this and I will soon. Due to the diverstiy of the sources(locations, they don't know each other, etc.) and the fact none of them have anything to gain by making a wishful forecast I trust them, especially since I have watched them all do very well on their verification in the past. BTW, the person that mentioned the possibility of wintry precip in FL nailed Charley's track/turn etc. and pretty much nailed each of the other FL landfalls too.

[Portastorm]

One private met in my area who is good but also generally forecasts conservatively has bought into the scenario as well as says that Christmas week could be a very wild week for those of us in the Southern Plains.

Only a matter of time before one of our NWS offices gives us the classic BEARS WATCH!!!

[sertorius]

I am hearing all this which makes the mid-upper 40's for Christmass seem a little wierd-I know they can have snow way south of me and us get sun, but usually when that happens this time of year, we are in the deep freeze. So basically, local mets and NWS here in KC MO are down playing this whole thing. I personally feel that the next couple of weeks will be quite interesting for us in the Central Plains as well. The models are showing this as a trend and the Western ridge is building-of course, it could all go east of us here-we shall see

[CaptinCrunch]

Monday's (12/13th) forecast for Dallas/Ft Worth has a high of 50 low of 29, I really don't think we will make it out of the upper 40's monday. Now I don't think this next front will say very long and it should warm slightly before the bottem falls out around the 19th give or take a day. After that you better have a good supply of firewood because we could have a repeat of 1989 when the deep freeze opened and we recorded the 3rd lowest temp on December 23, 1989 at -1 below.

As far as precip for that time frame it looks like a very cold rain maybe turning to a sleet/freezing rain situation for much of N centeral and NE Tx by Christmas Eve. If another surge of polor air comes down around the 23rd/24th then we may see some light snow by Christmas day night or the day after.

If the REX block developes and holds up then I think even Houston will see some freezing rain or sleet before the 25th. Looking at all the possible setups for this event the one thing I can say for sure is it will depend on the thickness of the cold air dropping south and IF we can get the SJS to help with the over riding without breaking down the REX Block off the West Coast.