Upcoming cold for the South (Models, Maps, Discussions)

[Tyler]

Despite many jabs from a lot of people on this board, the NWS hit this one on the head. Lows at IAH didn't even get below 30 - leaving many forecasts around here completely busted (I somewhat busted to as I thought upper 20's). Even more surprising - most areas of Houston did not see a hard freeze. IAH saw about 3 hours of below freezing conditions which may qualify - but if your typically warmer than IAH, you did escape a hard freeze. Maybe we all have a lot more to learn about arctic fronts.

Say hello to a high near 60 today with a lot less wind. Will feel a lot better than yesterday!

The reason I hate having airports as official temperature observation spots, is that they are nothing but heat islands. People will look at IAH and go, "well, it only hit 30, no hard freeze at my house". When in reality, the opposite thing occured. If I hit 24, I can guarantee you many other communities had a hard freeze as well. The NWS forecast last night, that called for mid 20s rural, around 30 urban, was SPOT on, and a very good forecast, except for highs saturday, which were a total bust. I treated IAH as if it were a rural area (the wind didn't help me). Even though IAH only hit 30, rural areas, such as me, hit the mid 20s, thus, a hard freeze was reached.

I don't want people to say there was no hard freeze last night, there was, just not in urban areas.

[JonathanBelles]

i know what u mean pie (st. pete0 has a temp of 52 but at my house its 44

[Tyler]

Now that the Big Freeze of 06 is over, I'm going to tip my hat to the NWS forecasters out of Austin/San Antonio.

They nailed yesterday's high in the low 50s and, in fact, were too cold for last night/this morning ... we hit a low of 30 at Camp Mabry (in the middle of the city) and upper 20s in outlying areas. I think the forecasted low was 24 or 25.

Credit should be given when due ... so, good job NWS!

Agreed....here were my predictions for last night....Taken from the KHOU board yessterday am.

IAH- 30-32 - on the $
Houston- 33-34 on the $
Pearland- 33-34 on the $
Sugarland- 30-32 bust
Conroe- 28-30 bust
Galveston -34-36 on the $
_________________

Good job on the forecasted numbers! I busted with my temps at the airports. Darn winds. I thought the pressure gradient would relax, but it didn't. Therefore, my numbers were too cool.

[cheezyWXguy]

i keep hearing about some kind of possible arctic outbreak in NTX where i live...can anybody fill me in on the details?

[cheezyWXguy]

i no how unreliable accuweather forecasts are but i they have a high of 38 for me on sat next week w/ rain...sounds like things may get interesting but thats all i know right now

[Tyler]

Here is my take on next weekend, and the upcoming pattern. This is mainly for the Houston area. I do not believe that we are in for any strong arctic outbreaks down here, however, points northward is a different story.

GFS and ECMWF both indicate that this season's coldest air yet will begin to filter into the northern plains this week. But will it make it here?

0z GFS, hour 78:
http://www.nco.ncep.noaa.gov/pmb/nwprod ... _078.shtml

First off, if you look at the 500mb map, notice that very strong ridge building into Alaska. It is becoming quite evident that the strong pac jet and EPO is dead, no longer are storms smashing into the Pac NW, not allowing any kind of ridge to build. This is also finally allowing strong high pressure centers to dive out of Canada, one of which just brought us the cold weather we are experiencing right now. Notice the 1048+MB developing in NW Canada, and also all those blue lines making a circle in central Canada, thats a piece of the polar vortex, dropping down into the northern plains! We've got 480's! Thats cold folks!

Hour 102:
http://www.nco.ncep.noaa.gov/pmb/nwprod ... _102.shtml

That is impressive. We've got an omega block in the pacific, which will destroy the progressive pattern we have seen all through January (its pretty much already been destroyed). We've got a zonal flow in the Lower 48, however, we have a 1056+MB high (thats very strong folks) diving into the northern plains, as well as the polar vortex. Now, if this was January, it would be likely that we would see a significant arctic outbreak this weekend(especially with such a strong high pressure), however, things aren't exactly right for that to happen.

If you look at those frames at hour 102, first its zonal flow. Thats not really good to send down cold air, unless you have a Feb 1989-like high moving in. Although we have a 1056, it won't be enough to push significant arctic air our way. It could be enough if it was just zonal flow, however, it appears a ridge is trying to develop in the gulf, if you look at the 500mb, you can notice how a strong southerly, or southwesterly flow, is developing, pumping any strong cold air away from here. That isn't good if you want strong cold fronts to reach this far south. Again, we are nearing March, and the jet stream is beggining to move farther north, and not being able to reach this far down here. Also, pressures are low in the west, which normally do not favor strong cold fronts to pass through.

132 hour:
http://www.nco.ncep.noaa.gov/pmb/nwprod ... _132.shtml

Ok, if we look at that, notice how frigid the northern plains, and the northeast are. They are literally in the freezer! However, the extremely cold air gets stuck in Oklahoma on its way down here, as the upper air pattern is extremely unfavorable for it to make it down here. The airmass will eventually make it down here, however, it will be weak, and very modified, and will pretty much be like a pacific front. This weekend, we will likely see cloudy and cool conditions (but not cold), it will also be wet, as we are in a southwest flow. Warm moist air will override the cool air, and provide overrunning, as well as other disturbances moving through.

In summary:

So basically, expect thursday and friday to be very warm and humid, with a slight chance of rain. Then on saturday, a cold front may move through, with a continued chance of rain. It will be cloudy, cool, and dreary, with highs likely stuck in the upper 50s, but lows probably not getting out of the 50s. I don't expect any outbreaks of cold air in SE TX, as the upper air pattern just does not support it right now. But in Dallas, they will be much colder than us, with highs likely stuck in the 40s, but lows will still be in the 40s as well. Again, nothing too terribly cold, as the coldest air is shunted north and east, away from the deep south. This pattern screams overrunning snow events for Oklahoma and points northward. Of course, things could change, but thats how I see it right now... BTW, this pattern reminds me alot of Feb 1979. The northern plains were VERY cold, as was the northeast, but the south stayed mild.

If the cold air that is building into Canada right now was there when the strong cold front moved through on friday, then things would be VERY different around here right now, and we would be likely talking about the coldest air in sometime around here.

A cool and wet weekend ahead!

[wxman22]

Well Tyler you have to look at more than just the GFS. This is a "classic" eror that the models make especcialy the GFS. Thr GFS just cant handle cold air this far south. The GFS hasnt even been consistent from run to run. Notice how compacted the 2m temps are. With that strong of a high the temps are not going to stop at the Red River and not go any farther south. Just as Wxman57 said on KHOU's forum. Will just have to watch and see.....

[Tyler]

Well Tyler you have to look at more than just the GFS. This is a "classic" eror that the models make especcialy the GFS. Thr GFS just cant handle cold air this far south. The GFS hasnt even been consistent from run to run. Notice how compacted the 2m temps are. With that strong of a high the temps are not going to stop at the Red River and not go any farther south. Just as Wxman57 said on KHOU's forum. Will just have to watch and see.....

I am not using just the GFS, I know better than to do that. I looked at the ECMWF as well, and it basically shows the same thing. The BITTERLY COLD AIR does not make it this far south, and is shunted east. However, like I said above, a very weak part of that airmass will make it down here, and put us into a dreary cool wet pattern, but nothing too terribly cold. This is my thinking as of right now. Things may change, but Feb 1979 is the best analog of the upcoming pattern. You can't get any cold air down here with an upper ridge trying to develop in the Gulf. You can get cool air, like we will this weekend due to such a strong high, but not cold.

Thanks Dan . I think we will see cooler air move in this weekend, and with clouds and rain chances around, it will be quite dreary, however, I think our chances of really cold air to make it down here are just about out. With a ridge trying to develop into the Gulf, your not going to get really cold air to make it this far south, and the zonal flow doesn't help much either. Then again, I could be completely wrong, the high pressure center could be much stronger than what models show, and the really cold air could make it down here since models do have a hard time with shallow airmasses, however, I just don't see that at this time...

This is the Euro, Day 7 Heights:


We need to get rid of those high heights down in Mexico which could help to build an upper ridge in the Gulf if we want cold air to come down here.

Again, I could be completely wrong, this is just my thinking right now. A cool wet and dreary weekend ahead, with bitterly cold air hung up to our north.

[Brent]

Local station has Wintry Mix Possible Saturday and Freezing Rain or Snow Sunday.

[Tyler]

Local station has Wintry Mix Possible Saturday and Freezing Rain or Snow Sunday.

Yup, overrunning pattern coming up. Great for snow events, but not so great for cold air to make too far to the south. (February 1979)

[Extremeweatherguy]

A tour of the morning AFD's:

AUSTIN

EXPECT MOIST AND MILD DAYS FOR WEDNESDAY AND THURSDAY FOR MOST
COUNTIES. MODELS ARE IN FAIR AGREEMENT ON A COLD FRONT PUSHING
CANADIAN AIR INTO THE AREA LATE FRIDAY MORNING. WITH A ZONAL
PATTERN ALOFT, THE STAGE LOOKS SET FOR A MULTIDAY OVERRUNNING
EVENT WITH THE SURFACE RIDGE BEING REINFORCED THROUGH THE WEEKEND
BEFORE THE FRONT ERODES NEXT MONDAY. ONCE AGAIN THE WEEKEND RAINS ARE
EXPECTED TO BE ON THE LIGHT SIDE; HENCE THE SLIGHT CHANC/LOW CHANCE
POPS.

DALLAS

THERE IS STILL PLENTY OF UNCERTAINTY REGARDING PRECIPITATION WITH
THE COOLER AIR MASS. WITH NO MAJOR SHORT WAVE TROUGHS MOVING ACROSS
THE AREA...IT APPEARS THAT THE PRECIP THAT OCCURS MAINLY WILL BE IN
RESPONSE TO ISENTROPIC LIFT OF AIR NEAR THE 925 MB TO 850 MB
LEVELS...RIDING NORTHWARD ABOVE THE COOL AIR MASS. THE BEST DAYS FOR
WARM ADVECTION INDUCED LIFT IN THE CURRENT GFS RUN ARE THURSDAY
EVENING...FRIDAY NIGHT...AND AGAIN NEXT SUNDAY. HOWEVER...THIS
LIKELY WILL CHANGE IN COMING MODEL RUNS. THUS...WE HAVE LEFT POPS
RATHER LOW.


HOUSTON

ANOTHER COLD FRONT IS EXPECTED TO CROSS THE REGION FRIDAY. GLOBAL
MODELS ARE IN GOOD AGREEMENT WITH THIS SOLUTION. FIND IT A BIT
ODD THAT A FRONT WILL SLIDE THROUGH THE REGION WITH A 500 MB
RIDGE BUILDING AND THE LACK OF A STRONG S/WV EXITING. THE STRONG
HIGH (1048 MB) WILL SINK SOUTH TOWARD THE MID-MISSISSIPPI VALLEY
ON SUNDAY. THE LACK OF SNOW COVER OVER THE CENTRAL PLAINS SHOULD
ALLOW THE AIR MASS TO MODIFY AS IT MOVES SOUTH SO HAVE WARMED
TEMPS ABOVE MEX GUIDANCE FOR SAT-SUN. CONFIDENCE THAT THE FRONT
WILL ACTUALLY CROSS THE COAST IS VERY LOW AS SURFACE PRESSURES ARE
MUCH HIGHER OVER THE EASTERN U.S. THAN THE WEST. RAIN CHANCES ARE
DEPENDENT ON THE FRONTAL POSITION. SINCE CONFIDENCE IS LOW...HAVE
ONLY GONE WITH A SLIGHT CHANCE FOR FRI-SUN. 43

[Extremeweatherguy]

Local temperatures as of 7am:
IAH = 33F

Hooks = 29F

Conroe = 26F

Hobby = 37F

My House = 27F

[jdray]

Cecil Field was at 23F according to the NWS this morning.

THey are forecasting another 24F night for Jacksonville, I might see upper teens at my house.

http://www.srh.noaa.gov/data/obhistory/KVQQ.html

[cheezyWXguy]

Well I know its the 06z GFS and any GFS shouldnt be taken as the truth...but it is starting to bring some colder air and possibly snow into near the wichita falls or childress area...(kinda close to me) a little bit later next week...
http://www.nco.ncep.noaa.gov/pmb/nwprod ... _204.shtml
^^incoming arctic front hr. 204
http://www.nco.ncep.noaa.gov/pmb/nwprod ... _252.shtml
^^possible snow event for NTX-hr 252

just something to look at

[cctxhurricanewatcher]

It looks like the models will have trouble with this one leading right up to the actual event which is the case with shallow, dense Arctic Air. What do the Pro Mets on here think about this weekend's front?

[Extremeweatherguy]

It looks like the models will have trouble with this one leading right up to the actual event which is the case with shallow, dense Arctic Air. What do the Pro Mets on here think about this weekend's front?

yes, pro met input would be greatly appreciated.

[cheezyWXguy]

I'm now starting to hear that the cold isnt going to make far enough south for it to snow in texas...but ive also been looking over the lastest GFS models(posted above) that a bigger shot may come mid next week...is that a possiblilty?

[Portastorm]

It looks like the models will have trouble with this one leading right up to the actual event which is the case with shallow, dense Arctic Air. What do the Pro Mets on here think about this weekend's front?

yes, pro met input would be greatly appreciated.

Yes CC, I think you're right on the money with that assessment. This is going to be a challenging week for meteorologists in the southern Plains as they look toward the weekend.

[cheezyWXguy]

yay! the 12z GFS is coming in...hopefully the consistency is a little better today than it was yesterday

[Tyler]

I'm now starting to hear that the cold isnt going to make far enough south for it to snow in texas...but ive also been looking over the lastest GFS models(posted above) that a bigger shot may come mid next week...is that a possiblilty?

Anything is possible, however, the upper air pattern is extremely unfavorable for any more cold arctic shots for Texas next weekend, other than a weak push of cool air. Next weekend looks cool, cloudy, wet, and dreary for Texas. But nothing very cold at all.

It must be noted that there are increasing chances of snow or ice storms next week for the Plains and Tennessee Valley. Overrunning galore.