(New!!) Cold for the Deep South (Models, Maps, Discussion)

[JonathanBelles]

wait a minute, were supposed to get in the mid 70's this weekend in Pensacola, but there is a chance of snow in the south?

im sposed to reach 80 and snow yes

[PTrackerLA]

Seems like the models are backing off on next weekend's cold front. The NWS offices around here don't think that the cold front will even make it through the area. I would love to have another good cold front, it's been nice to have it feel like winter again around here after the miserable January.

[Extremeweatherguy]

Seems like the models are backing off on next weekend's cold front. The NWS offices around here don't think that the cold front will even make it through the area. I would love to have another good cold front, it's been nice to have it feel like winter again around here after the miserable January.

they are not really backing off; in fact they are showing all the right ingredients for a major arctic blast, but yet they are showing the cold all bottled up to the north. There is some sort of error going on with the models...they are not taking into account the shallow cold air that may spill down the plains. At this point we are still in the wait and see mode. Here in Texas, some NWS offices are calling for the arctic air and others are not...and to add into the mix of confusion, JB from Accuweather is calling for major cold down the plains and through the east over the coming week or two and he says that big ice storms may be a threat in the southern plains and SE. Really weird situation right now. Can't wait to see the 18Z and 0Z GFS later today.

[SouthFloridawx]

000
AXNT20 KNHC 121745
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SUN FEB 12 2006.....


...DISCUSSION...

GULF OF MEXICO...
COLD-AIR STRATOCUMULUS COVER MOST OF THE GULF SAVE ALONG THE
IMMEDIATE COAST WITHIN 30-45 NM. GALES HAVE LEFT THE GULF AS
THE E COAST NOR'EASTER DEPARTS THE AREA. THE COLDEST NIGHT OF
THE SEASON IS LIKELY FOR MOST OF FLORIDA AS COOL AIR SPILLS INTO
THE STATE. THE ONLY THING THAT MAY KEEP THE PENINSULA FROM
GETTING TOO COLD IS THE CLOUDY SKIES THAT WILL LIKELY CONTINUE
OVERNIGHT... PERHAPS PUSHING THE COLDEST DAY BACK UNTIL TUE
MORNING. UPPER TROUGH AXIS EXTENDS FROM NW FLORIDA INTO THE SW
GULF OF MEXICO WHICH SHOULD HELP TO DRY OUT THE ATMOSPHERE A
LITTLE OVERNIGHT. HOWEVER A SECOND UPPER TROUGH IS DIVING DOWN
THE BACK SIDE OF THE TROUGH.. CURRENTLY NEAR ARKANSAS... AND
COULD BRIEFLY CAUSE A PERIOD OF LIGHT SPRINKLES OR EVEN FLURRIES
IN CENTRAL FLORIDA AROUND THE TAMPA AREA EARLY TOMORROW
MORNING. A WARM-UP IS EXPECTED AFTER TUESDAY.

[jdray]

http://www.srh.noaa.gov/ifps/MapClick.p ... L&site=JAX

NWS Jax keeps dropping thier forecast temps.

Now down to 27 tonight, 23 tomorrow night.

[JonathanBelles]

http://www.srh.noaa.gov/ifps/MapClick.php?CityName=Middleburg&state=FL&site=JAX

NWS Jax keeps dropping thier forecast temps.

Now down to 27 tonight, 23 tomorrow night.

i dont like that forecast because it is 5 degrees higher than the actual here

[aggiecutter]

Today's CPC guidance brings the cold air all the way down to the GOM in its 6-10 and 8-14 day outlooks.

http://www.cpc.ncep.noaa.gov/products/forecasts/

[Extremeweatherguy]

Today's CPC guidance brings the cold air all the way down to the GOM in its 6-10 and 8-14 day outlooks.

http://www.cpc.ncep.noaa.gov/products/forecasts/

Very interesting. You should check out the Dallas and Houston AFD's this afternoon. Dallas is calling for the cold to arrive Friday and for it to be quite cold...and Houston is calling for the front on Saturday night and are un-sure how cold it will be. Looks interesting to say the least. I just hope that Dallas is right with their idea of a very cold shallow airmass.

[aggiecutter]

The noon Ensembles run has the flow coming straight out of Siberia into the lower 48 from about 96hrs on...
http://wwwt.emc.ncep.noaa.gov/gmb/ens/t ... 21212.html

[beachbum_al]

I was wondering the same thing...I know next week they are saying highs in the 70s for my area and this thing about a snow storm...?

[JonathanBelles]

is there such a thing as gulf effect snow?

[plainsman]

beach, the brunt of the arctic air will be over Texas and Oklahoma instead of the southeast.... this front looks to be a blue norther.. (arctic air that dives from canada straight down thru thru the southern plains into tx and ok and stalls there) some arctic air may drift over into northwestern alabama giving them a slight chance of wintry precip... it just depends what part of alabama do you live in?

[cctxhurricanewatcher]

Today's CPC guidance brings the cold air all the way down to the GOM in its 6-10 and 8-14 day outlooks.

http://www.cpc.ncep.noaa.gov/products/forecasts/

Very interesting. You should check out the Dallas and Houston AFD's this afternoon. Dallas is calling for the cold to arrive Friday and for it to be quite cold...and Houston is calling for the front on Saturday night and are un-sure how cold it will be. Looks interesting to say the least. I just hope that Dallas is right with their idea of a very cold shallow airmass.

Typical lack of coordination again. What's new?

I know. We don't criticize the NWS around here.

Opps.

[beachbum_al]

beach, the brunt of the arctic air will be over Texas and Oklahoma instead of the southeast.... this front looks to be a blue norther.. (arctic air that dives from canada straight down thru thru the southern plains into tx and ok and stalls there) some arctic air may drift over into northwestern alabama giving them a slight chance of wintry precip... it just depends what part of alabama do you live in?

I am as far south in Alabama as you can get. Well close to it. I guess I will not see any. I have enjoyed the 20s that we are having this weekend though. It was nice and cold on the beach this morning. I will share pics later.

[Extremeweatherguy]

The latest 18Z GFS run is coming in...and here is what it is showing:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _126.shtml
^^at 126 hrs. it shows a 1052mb+ high in the northern plains. This would suggest that a shallow layer of cold would be sent south through the plains...but as you can see...the model is still having trouble. Look at the giant temp. difference it has shown through the state of TX on day 6. I doubt it would be that extreme. It does show widespread light moisture over TX though, so if the shallow cold airmass can come south through the state, then ice may be an issue.

[Extremeweatherguy]

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _132.shtml
^^the 18Z GFS looks just way too Zonal for the pattern (this is hr. 132 by the way)^^

[gboudx]

Norman's AFD points the precip to their south and east for end of this week. And they are looking at freezing precip vs frozen. I'm looking forward to the DFW and San Angelo AFD's.

[Tyler]

Well, I posted this in the other south cold thread, so since there are two of these threads, I guess I'll post my same thoughts in here as well...

Ok, I've made a map of the upcoming pattern for this weekend. I whiped this up pretty quickly so its not that great ...



First off, a strong high pressure system will dive out of Canada, bringing with it the coldest air of the season to affect the lower 48. It will be downright frigid for the Plains and northeast.

For the midwest, an area of low pressure will track across the area, bringing with it a chance of significant snowfall for many people, around Thursday. Lucky you! A great pattern for the midwest.

For the northwest, it will become MUCH colder, as arctic air sweeps into the region, and snow levels will drop to near sea level. This will open up the chance for Seattle and Portland to recieve quite a few chances of some snow!! Great pattern for Pac NW.

For the northeast, after a chance of rain on Friday, an arctic front will move through, bringing with it BITTERLY cold, and I mean BITTERLY FRIGID COLD temperatures will dominate the region. You guys better be prepared for that.

For the South, here is where the trouble lies. As the bitterly cold air stays bottled up in the plains and northeast, just a dap of some of that cold air will push to the south all the way into the Gulf. This air will be cold, but shallow, but still nowhere near as cold as in the midwest. The problem in getting bitterly cold arctic air down this far south is the zonal flow across the US, and an upper ridge developing in the Gulf, as well as too low of pressures in the west, this will help to squash any REALLY cold air to move down here. However, due to such a strong high pressure system, a bit of cold air will slowly move down here. There will also be a southwest flow with this shallow cold air around. And there is the problem. ICE POTENTIAL. Overrunning will produce a chance of frozen precip for OK, TN, NC, and SC, and northern areas of TX, AL, MS, and GA. With the shallow cold air around, freezing rain or sleet may occur. Snowflakes are possible, but it won't be cold enough at all levels to support this. This setup has huge potential for an ice storm, but right now, to exactly pinpoint exactly when and if this happens is a bit difficult. We are still a bit too far away to tell exactly when the best chance of icing to occur. My advise is for people living in those areas to keep up with the latest forecasts from the NWS and your local media, as things could get interesting.

Meanwhile, south of that area, it will be very cool, cloudy and dreary, with increasing chances of plain ol rain. Much-needed rain! But not cold, as the arctic air stays north of the region.

Well, those are my thoughts right now...

[Extremeweatherguy]

I posted this on the other thread too, so I will also post it here:

I don't know if I completely agree with you this time Tyler. I think it will be more than just "cool" here in Houston. Remember, compared to averages, "cool" in February is like 60F for a high. I think we will be much below 60F during this upcoming weekend with clouds and rain. I also think that chances for ice reach as far south as Austin and College station during the night time hours (as lows of AT LEAST 30-35F will be common in those areas)...in fact, I would not even be surprised if Houston saw some ice from this situation (and I hope we do). Also...I think the NWS may be more in line with the situation. Currently they are forecasting 50s for the weekend with lows near 40F..but they also stated in their discussions that ALL major models are trending colder. Here is the latest Houston AFD:

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
226 PM CST MON FEB 13 2006

.DISCUSSION...
WEAK HIGH PRESSURE OVER CWFA EARLY THIS AFTERNOON. WINDS ALREADY
PICKING UP FROM THE SOUTH OVER NORTHERN PORTIONS OF CWFA DUE TO
FALLING PRESSURES OVER NW TX. DEWPOINTS QUITE LOW ACROSS REGION
...IN THE MID AND UPPER TEENS. WATER VAPOR LOOP INDICATE RAPIDLY
MOVING NW TO SE SHORT WAVE OVER COLORADO. THIS ENERGY WILL MOVE
ACROSS TX TOMORROW. LACK OF MOISTURE WILL PRECLUDE ANY CHANCE OF
PRECIP FROM THIS FAST MOVING UPPER LEVEL DISTURBANCE. LOW LEVEL
MOISTURE WILL GRADUALLY INCREASE LATE TONIGHT WITH ONSHORE FLOW.
MID LEVELS INDICATED TO REMAIN RELATIVELY DRY BY GFS AND NAM THE
NEXT SEVERAL DAYS ALTHOUGH HIGH LEVEL CLOUD COVER EXPECTED TO
INCREASE BY MID WEEK. WARMING TREND WILL CONTINUE FROM TOMORROW
THROUGH AT LEAST EARLY FRIDAY. EXPECT TEMPS TO GO UP CLOSE TO 20
DEGREES ABOVE SEASONAL NORMAL VALUES MID TO LATE THIS WEEK.
NORTHWEST FLOW ALOFT WILL GRADUALLY BECOME ZONAL AS LARGE VORTEX
OVER NORTH- CENTRAL CANADA START TROUGHING MORE TO THE WEST BY
MID WEEK. UPPER LEVEL FLOW OVER OUR REGION BECOMING MORE WSW
TOWARD END OF WEEK. THIS IS WHEN LARGE HIGH PRESSURE (CANADIAN
ORIGIN) START TO PUSH SSE FROM WESTERN CANADA. SHALLOW
COLD DOME OF AIR WILL TRY TO PUSH ACROSS THE NORTHERN PART OF OUR
CWFA PROBABLY LATE FRIDAY AND THEN PUSH FARTHER SOUTH FRIDAY NIGHT
/EARLY SATURDAY. CANADIAN/GFS AND ECMWF ARE GETTING CLOSER IN
SOLUTIONS WITH LATE WEEK TO WEEKEND SCENARIO. SHALLOW COLD AIR
EXPECTED TO OVER OUR REGION THIS WEEKEND. HARD TO SAY FOR NOW IF
THERE WILL BE ANY (OR ANY OF ANY SIGNIFICANCE) UPPER LEVEL
IMPULSE(S) MOVING ACROSS THE WSW FLOW ALOFT (OVER OUR REGION) DURING
THIS PERIOD. HOWEVER...GFS INDICATE SOME MOISTENING AT THE MID
AND UPPER LEVELS SATURDAY/SATURDAY EVENING. FOR NOW...WE WENT WITH
LOW SIDE OF CHANCE CATEGORY FOR FIRST HALF OF WEEKEND. INDICATIONS
ARE THAT A WARMING TREND WILL FOLLOW EARLY NEXT WEEK WITH DRYING
AT MID/UPPER LEVELS. WE SHALL STAY CLOSE TO GFS MOS GUIDANCE
NUMBERS FOR TEMPERATURES THIS WEEKEND. 37


...looks interesting to say the least...

[Tyler]

I said it will be in the 50s as well. I never said it wouldn't be. And models aren't trending colder, they are trending closer together as far as timing is concerned... However, becuase of the upper air pattern, the farthest south ice could reach would be Waco. Austin and College Station should be fine. Due to clouds and rain, I don't think anyone will see 30s this weekend, mid 40s at best. This airmass coming in is not that cold. Cold enough to support freezing rain in Dallas, however. That is my concern. Wet and dreary weekend ahead.

Extreme, you have to look at the upper air pattern man. Low pressures in the west, a gulf ridge, and zonal flow do not send arctic air to Houston. Even with a massive 1056MB high, the ridge will do its part to only send us a modified, almost pacific like, airmass. My concern is Dallas. Major icing potential coming up.