Hey Weather Manny: Part Deux

[1369]

Late next week shaping up for another pipe buster?


WINDS IN THE LOWER BOUNDARY LAYER ARE RESPONDING TO THE UPPER LOW AS IT MOVES EAST OVER NORTHERN MEXICO AND HAVE TURNED TO THE SOUTHEAST. THIS WILL ALLOW FOR MOISTURE ADVECTION IN THAT LAYER LATER TODAY...WITH CLOUDS MOVING OVER OUR AREA AND SKIES BECOMING OVERCAST TONIGHT. HAVE INCLUDED A MENTION OF THUNDER AFTER MIDNIGHT WITH CONVECTION POSSIBLY EMBEDDED IN STRATIFORM RAIN GIVEN THE SPC DAY ONE OUTLOOK AND FORECAST MID LEVEL LAPSE RATES. POPS AND QPF WILL BE GREATEST ACROSS OUR EASTERN-MOST COUNTIES FRIDAY NIGHT INTO SATURDAY MORNING...BUT NOT SIGNIFICANT GIVEN THE FORECAST PROGRESSION OF THE UPPER LOW AND PUNY PWATS. WEST OR NORTHWEST WINDS WILL MIX DOWN TO THE SURFACE ON SATURDAY AS THE LOW EXITS TO THE EAST...ALLOWING TEMPS TO WARM INTO THE 60S. A COLD FRONT WILL FOLLOW ON SATURDAY NIGHT...WITH TEMPS DIPPING BACK DOWN BELOW SEASONAL AVERAGES. CHANCES FOR PRECIP WILL COME BACK TO THE FORECAST ON MONDAY NIGHT AS THE SHALLOW...MODIFIED CANADIAN AIRMASS IS OVERRUN BY GULF MOISTURE IN ADVANCE OF APPROACHING SOUTHERN BRANCH ENERGY. PRECIP WILL STAY IN THE FORECAST THROUGH THURSDAY AS THE SOUTHERN BRANCH REMAINS ACTIVE. BY LATE NEXT WEEK...A VERY COLD PATTERNS SETS-UP WITH GOOD POLAR TRANSPORT ALLOWING AN ARCTIC AIRMASS TO MOVE SOUTH TOWARD OUR AREA.

[MannyIsGod]

Not this far south. At least not the model runs I've looked at. It does look like a huge arctic breakout, but without a high pressure to the east it looks to go further east and not as far south. It looks dry too.

You never know though, it could happen. Just doesn't look like it yet.

[1369]

From ImpactWeather (subscription service)


Major Arctic Outbreak Likely Late Next Week
Issued: 10:54 AM CST Friday January 26, 2007




Major Arctic Outbreak Expected in Early February

For the past 7-9 days, long-range models have been predicting a major Arctic outbreak for the first week of February. We've talked about this outbreak on our daily Storm Development Outlook and on the StormWatch Daily Briefing video. Our confidence in the Arctic outbreak continues to grow each day. Today we will spell out what we're confident in, what has a good chance of occurring, and what type of weather is possible with such an outbreak.

What We're Confident In:

The Polar jet stream will be diving southward across the U.S. next week, transporting very cold air southward across much of the U.S. during the first week of February. Although some very cold Canadian air will be plunging down the Plains states by late this weekend, the leading edge of the coldest Arctic air will move into the northern tier of states from Montana to Minnesota by next Thursday, February 1st. This Arctic front should reach the Gulf Coast by around the 3rd or 4th of February -- next weekend. Unlike the last Arctic outbreak, this front will likely contain much colder air and deeper cold air. This means that the southeast states will not likely escape some very cold temperatures. As for duration, we think that the cold air may remain in place through the second week of February, possibly longer. What this means for the northern Gulf of Mexico is a prolonged period of strong north and northeasterly winds with rough seas beginning late next week.

What's Becoming More Likely:

Not only have the models consistently indicated the flow from the Arctic Circle to the central U.S., they've also been consistent in predicting that there will be a number of upper-level disturbances tracking across the Gulf Coast states once the cold air is in place. At the very least, this would mean clouds lingering behind the Arctic front, keeping high temperatures well below normal. But there is a very good chance that such a pattern would lead to some significant snowfall across north Texas, Oklahoma, and Arkansas by late next week into the first week of February. Perhaps as much as 6-12 inches of snow could fall across this region.

Variables:

1. We aren't yet confident just how cold it will eventually get across the central and southern U.S. with this outbreak, including the Gulf Coast.

2. We're also unsure about the southward extent of any freezing and frozen precipitation. It appears that this airmass may have a deeper sub-freezing layer than the previous Arctic front. That would mean a greater chance of snow and sleet, possibly down to the Gulf Coast. But our confidence that freezing/frozen precipitation will affect the southern parts of the Gulf Coast states is low.

3. Timing of any freezing/frozen precipitation events is uncertain. Such events will be driven by fast-moving small-scale weather features that may not be clearly evident until several days before any potential event.

What's Possible:

This cold outbreak could rival some of the major outbreaks in the 1980s that produced sub-freezing temperatures down to the Gulf coast for days at a time. In terms of cold, we think it's possible that low temperatures across the northern tier of states could reach -20F to -30F. The sub-zero temperatures could reach as far south as the Texas Panhandle east through central Oklahoma and Arkansas then northeast to the Mid Atlantic Coast. Across the Gulf Coast from Texas to the Florida Panhandle, low temperatures could reach the low 20s or even the upper teens, though 20s is more likely at first with the post-frontal cloud cover and potential post-frontal precipitation. Such an outbreak could produce sub-freezing high temperatures from the mid Texas coast to the Florida Panhandle by the 4th to 6th of February. But the above is just a possibility. Until the Arctic air is on the move southward, we won't be sure if the core of coldest air will move southward down the Plains or south! eastward across the Midwest.

As far as the chances of post-frontal precipitation, it's possible that disturbances moving across the well-established cold air could result in mixed freezing rain, sleet, and snow down to the Texas coast and east across coastal sections of Louisiana and Mississippi after the 3rd of February. With deeper cold air than the last outbreak, there may be a greater chance that more of the wintry precipitation may fall as snow down to the Gulf Coast. Again, we have very low confidence in a Gulf Coast ice storm, but the possibility is there.

Besides the Gulf Coast threat, such a flow pattern would favor the development of one or more major east coast snow storms - Nor'easters. Although none of the long-range models specifically shows any such storm development, it's quite possible that at least one and maybe two major snow storms will develop along the east U.S. Coast during the first week or two in February.

Meteorologist: Chris Hebert

[MannyIsGod]

The GFS shows the subfreezing layer staying in North Texas but that could change easily. However, its really hard to nail things down with that sort of accuracy this far out. As you notice he says that the SE states are likely to get hit this time, and thats becuase there's no blocking ridge there to force the cold air this way like I said above.

It'll be interesting and fun to watch though.

That looks like a cool subscription service, I'll have to check it out.

[MannyIsGod]

Oh, n/m. That probably costs a pretty penny. I hope to work for a company of that nature one day. :)

[MannyIsGod]

The First In A Series Of Cold Air Surges Of Arctic
Origin Arrive Thursday With Overrunning Cold Rain. Progressively
Colder Arctic Air Will Follow Next Weekend As Omega Block Sets Up
From The Canadian Northwest Territories South To Along The
Northwest U.s. Coast. A Wintry Mix Could Accompany The Colder Air
Next Weekend Depending Upon Whether Or Not The Southern Stream
Remains Active. Out This Far In Advance...models Cannot Resolve This
Sufficiently So Outlook Remains Murky. Stay Tuned.

[CubanMustGo]

If North Texas (not the panhandle) gets 6-12 inches I'll be incredibly surprised. I think the most we have seen in my seven years here is 2 or maybe 3".

[AlamoSpursFan]

Sounds like bullshit to me.

Sincerely,
Algore

[T Park]

:lmao

Im rooting for it.

Very cold weather = less work next weekend :) :) :) :) :) :)

[Shelly]

Steve Browne says possible wintery mix mid next week.

Agree?

[MannyIsGod]

Late next week looks chilly, thats about it.

[ShoogarBear]

Speaking of pipe busters, did you ever find out who that was in your sig, 1369?

[Shelly]

http://images.ibsys.com/ant/images/weather/auto/5day_320x240.jpg

[T Park]

SWEET.

Wintry mix rocks...