February 1-5, 2011 Arctic Blast/Winter Storm Discussion

[Andrew]

Euro came in about the same as last run temperature wise from what I can read. Nothing significantly different.

Check out low to the west:

[cristina99]

could you elaborate on the last the poast - about what the euro saw last night or early this morning?

[srainhoutx]

could you elaborate on the last the poast - about what the euro saw last night or early this morning?

The Euro as well as other models are suggesting an Upper Air disturbance will linger to our W after the Arctic Cold front passes on Tuesday. There appears to be some moisture as well, but not much and as we have seen this is a long way out in model world. What the overnight run have suggested is that it's going to get cold, mighty cold and likely the coldest of the season. Cloud cover may well be likely as well as some severe/heavy rainfall chances on Tuesday as the front pushes in from our N and W. As Jeff mentioned yesterday, the front looks to slide straight S into Deep S TX and move S and E. The model are converging on a solution regarding the front and drying conditions after the front passes. Then we have that lingering disturbance to our W. That may well suggest cloud cover and very chilly temps most of mid to late week. Should there be enough moisture and the lower levels moisten up enough, then we could see a very slight chance of something wintry reaching the ground. Still way too much uncertainty to speculate on anything further than that. The bottom line is a strong Arctic cold frontal air mass will settle across TX and our area and points E. I also wanted to show some temp changes over the past 24 hours. Note the 'cool down' just N of the US/Canadian Border. The Arctic air mass is still to the N of that area and heading S...

[srainhoutx]

SPC Update: SLIGHT Risk of Severe Wx for much of Southeast TX Saturday eve. Damaging winds, large hail the main threats....isolated tornado cannot be ruled out.

http://www.spc.noaa.gov/products/outlook/day1otlk.html

I don't know about there being too much severe weather. The air is really stable and it would have to become unstable really fast. Clouds will roll in too. Anything's possible though! It's been awhile since a bonifide severe weather outbreak around here recently.

SPC believes destabilization will occur towards late afternoon and early evening, eroding the cap...thereby producing elevated tstms. We should reach about 1000 j/kg by night fall, with support for rotating updrafts overnight, according to SPC. I'm guessing they had grounds for upgrading to slight risk for such a large area...which didn't seem to occur with the past few fronts...even though there was isolated severe.

I've stickied or pinned the January Discussion thread. Let's keep our discussions concerning this weekend in that thread as it is still January and a lot of folks are wanting information with the running of the Chevron Marathon tomorrow.

http://forums.khou.com/viewtopic.php?f= ... start=2210

[srainhoutx]

Euro ensemble mean (850mb temps) for Tuesday night/early Wednesday morning...

[wxman57]

Overnight GFS at least sees the cold air for a change. But don't get your hopes up for any frozen precip here. This just isn't the pattern for snow in Houston. The precipitation will fall with temperatures well above freezing on Tuesday. There is a chance that the Arctic air will slip south more quickly than the models are indicating, but this may mean freezing rain to our north, not snow in Houston.

[srainhoutx]

A look a GOES W Water Vapor Imagery shows our next week trouble maker off the Pacific NW spinning up as well as tropical thunderstorms associated with yet another Upper Low N of the Equator and E of HI...

[srainhoutx]

The 12Z NAM suggests a mighty potent Winter Storm across the Central and Southern plains...

[sleetstorm]

A look a GOES W Water Vapor Imagery shows our next week trouble maker off the Pacific NW spinning up as well as tropical thunderstorms associated with yet another Upper Low N of the Equator and E of HI...

http://weather.unisys.com/satellite/sat ... oop-12.gif

Wow! It is a very long way away from land.

[srainhoutx]

The 12Z GFS suggests a deeper trough as our Upper Air disturbance dives S into N MX...that model is trending colder as well...

01292011 12Z GFS f72.gif

01292011 12Z GFS f84.gif

01292011 12Z f102.gif

01292011 12Z GFS f114.gif

01292011 12Z GFS f126.gif

01292011 12Z GFS f132.gif

01292011 12Z GFS f150.gif

[biggerbyte]

As of today, nothing has changed. We are right on track for the same old. We'll look at again on Sunday. Time is ticking away to gain any confidence at all in any big winter fun for s.e Texas. There are some possibilities via some of the models, but as with this entire season so far, nothing but nothing materializes in the end.

We have another day or so, so let's not write it off just yet.

BB

[Andrew]

The 12Z GFS suggests a deeper trough as our Upper Air disturbance dives S into N MX...that model is trending colder as well...

WOW! Now the GFS is by far the coldest while the Euro and CMC have trended warmer. That is some cold air right there. I think the GFS is starting to pick up on things.

EDIT:

GFS is showing 2m temps down to -5.7C or around 21F (IAH)!

[srainhoutx]

A big step in the right direction (correction, if you will) for the GFS concerning that cold air. In fact that model suggests we will stay cold through Friday.

[Andrew]

A big step in the right direction (correction, if you will) for the GFS concerning that cold air. In fact that model suggests we will stay cold through Friday.

Yea 850mb temps reach all the way to -11C! This is different.

The gfs is very close to a freeze from Wend-Fri

[wxman57]

I still see nothing to indicate any "threat" of winter weather in our area. Even if the worst-case scenario plays out (Arctic air slips south faster than models are projecting), all we'd see would be colder rain vs. warmer rain. Any snow threat is in north to northeast Texas, not in our area.

[srainhoutx]

I still see nothing to indicate any "threat" of winter weather in our area. Even if the worst-case scenario plays out (Arctic air slips south faster than models are projecting), all we'd see would be colder rain vs. warmer rain. Any snow threat is in north to northeast Texas, not in our area.

Well the 12Z Canadian (GEM) suggests otherwise...

01292011 12Z GEM 12_054_G1_north@america@zoomout_I_4PAN_CLASSIC@012_132.jpg

01292011 12Z GEM 12_054_G1_north@america@zoomout_I_4PAN_CLASSIC@012_144.jpg

[biggerbyte]

I still see nothing to indicate any "threat" of winter weather in our area. Even if the worst-case scenario plays out (Arctic air slips south faster than models are projecting), all we'd see would be colder rain vs. warmer rain. Any snow threat is in north to northeast Texas, not in our area.

Ditto!!! Sorry, guys. In reality, as of now, it's just not there.

[ronyan]

I still see nothing to indicate any "threat" of winter weather in our area. Even if the worst-case scenario plays out (Arctic air slips south faster than models are projecting), all we'd see would be colder rain vs. warmer rain. Any snow threat is in north to northeast Texas, not in our area.

Ditto!!! Sorry, guys. In reality, as of now, it's just not there.

The cold air is though.

[wxman57]

12Z GFS has a very rainy marathon tomorrow morning, and a couple of days with lows in the low 20s and highs in the upper 30s Wed/Thu. Canadian is the only model indicating that the upper low to the west might move east on Wed/Thu. If it did, though, our lows would be a good bit higher than the low 20s due to clouds. Need to wait for the Canadian on the Penn State ewall site to update as it has 850mb temps on it.

[wxman57]

Local NWS office doesn't mention the cold yet. Just a light freeze Thursday night. They've trended from going with guidance (GFS) to going well above guidance since yesterday. I guess they don't believe the cold air is coming down here...

HARRIS-
INCLUDING THE CITIES OF...HOUSTON...HUMBLE...KATY...PASADENA... TOMBALL
1007 AM CST SAT JAN 29 2011

TUESDAY...CLOUDY. SHOWERS AND THUNDERSTORMS LIKELY IN THE
MORNING...THEN A CHANCE OF SHOWERS AND THUNDERSTORMS IN THE
AFTERNOON. HIGHS IN THE UPPER 60S. CHANCE OF RAIN 60 PERCENT IN
THE MORNING DECREASING TO 50 PERCENT IN THE AFTERNOON.

TUESDAY NIGHT AND WEDNESDAY...MOSTLY CLOUDY. MUCH COOLER. LOWS
IN THE UPPER 30S. HIGHS IN THE UPPER 40S.

WEDNESDAY NIGHT...MOSTLY CLOUDY IN THE EVENING THEN BECOMING
PARTLY CLOUDY. LOWS IN THE LOWER 30S.

THURSDAY AND THURSDAY NIGHT...PARTLY CLOUDY. HIGHS IN THE MID
40S. LOWS AROUND 30.

FRIDAY...PARTLY CLOUDY. HIGHS IN THE LOWER 50S.