January Weather Discussion: Slight Chance Severe Storms

[srainhoutx]

The cold front is making progress and is heading in our direction. Front has passed Waco/Austin/San Antonio at this hour. Rain is increasing in S/Central TX as well as a surface low forms near Corpus Christi...

[cristina99]

so all this talk isn't about this front tonight / tomorrow right? We're talking about the arctic blast next week. What is the proposed time frame? I guess we would need to use next weekend (say Saturday) to prepare. Please explain in simple terms, what the latest models show. Does it still look like we are going to get some bitterly cold air?

[TexasMetBlake]

I am at work and haven't had a chance to look yet, but my friend at HGX just texted me and said that the 18z gfs shows a 'major icing event' in southeast Texas around the 2nd.

BTW, is it gramatically correct to say 'texted'?

[Ptarmigan]

I am at work and haven't had a chance to look yet, but my friend at HGX just texted me and said that the 18z gfs shows a 'major icing event' in southeast Texas around the 2nd.

BTW, is it gramatically correct to say 'texted'?

384 Hour GFS Forecast. Includes February 2.

Code: Select all

FIELD  TEMPERATURE   DEW POINT       TEMPERATURE    TEMPERATURE    PRECIPITATION  AVG TTL CLD CV
LEVEL      2M             2M           850 MB         500 MB                               
UNITS      DEGC            DEGC          DEGC           DEGC           MM              PCT 
 HR
+  0.      4.6            3.4            4.9          -19.0           3.17           99.2
+ 12.      2.0            1.2            4.2          -18.2          13.51           99.8
+ 24.      2.1            0.8            5.1          -17.6           6.59           97.8
+ 36.      0.9            0.2            5.6          -18.5           6.28           98.8
+ 48.      3.3            2.3            4.9          -20.1           2.34           97.2
+ 60.      2.5            1.9            6.6          -15.0           0.93           46.0
+ 72.     11.8            8.8            8.1          -14.5           0.00            9.9
+ 84.      8.2            7.6            8.5          -15.8           0.00            3.3
+ 96.     15.2           12.8            5.7          -15.6           0.01           46.4
+108.     14.5           14.1            9.8          -15.1           0.98           65.4
+120.     18.6           16.9            9.1          -14.2           3.24           86.3
+132.      5.5            4.0            5.4          -14.2           1.93           71.0
+144.      4.5           -1.5            5.3          -15.3           0.19           77.8
+156.      2.2           -0.6            6.1          -12.8           0.00           11.2
+168.      8.0           -2.3            3.7          -14.1           0.00           16.3
+180.      1.7           -2.5            1.1          -14.1           0.06           17.7
+192.      3.6           -8.0            0.5          -15.3           0.12           21.8

Texted I am sure is grammatically correct.

[srainhoutx]

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0642 PM CST SUN JAN 23 2011

VALID 240100Z - 241200Z

...NO TSTM AREAS FORECAST...

...SOUTH TX COAST...
AIRMASS MODIFICATION/MOISTURE RETURN CONTINUES TO OCCUR OVER THE
WESTERN GULF OF MEXICO/TOWARD THE LOWER TX COAST...AS LOW LEVEL
MOISTENING/CAP REMOVAL HAS OCCURRED SINCE EARLY TODAY PER 00Z
OBSERVED RAOBS FROM BROWNSVILLE/CORPUS CHRISTI. REGARDLESS...MODEST
FORCING COMBINED WITH MARGINALLY FAVORABLE THERMODYNAMIC PROFILES
IMPLY TSTM POTENTIAL WILL BE LOW INLAND...WITH ANY TSTMS LIKELY
CONFINED TO THE OPEN GULF WATERS OFF THE LOWER/MIDDLE TX COAST LATE
TONIGHT/EARLY MONDAY.

..GUYER.. 01/24/2011

[Andrew]

I am at work and haven't had a chance to look yet, but my friend at HGX just texted me and said that the 18z gfs shows a 'major icing event' in southeast Texas around the 2nd.

BTW, is it gramatically correct to say 'texted'?

384 Hour GFS Forecast. Includes February 2.

Code: Select all

FIELD  TEMPERATURE   DEW POINT       TEMPERATURE    TEMPERATURE    PRECIPITATION  AVG TTL CLD CV
LEVEL      2M             2M           850 MB         500 MB                               
UNITS      DEGC            DEGC          DEGC           DEGC           MM              PCT 
 HR
+  0.      4.6            3.4            4.9          -19.0           3.17           99.2
+ 12.      2.0            1.2            4.2          -18.2          13.51           99.8
+ 24.      2.1            0.8            5.1          -17.6           6.59           97.8
+ 36.      0.9            0.2            5.6          -18.5           6.28           98.8
+ 48.      3.3            2.3            4.9          -20.1           2.34           97.2
+ 60.      2.5            1.9            6.6          -15.0           0.93           46.0
+ 72.     11.8            8.8            8.1          -14.5           0.00            9.9
+ 84.      8.2            7.6            8.5          -15.8           0.00            3.3
+ 96.     15.2           12.8            5.7          -15.6           0.01           46.4
+108.     14.5           14.1            9.8          -15.1           0.98           65.4
+120.     18.6           16.9            9.1          -14.2           3.24           86.3
+132.      5.5            4.0            5.4          -14.2           1.93           71.0
+144.      4.5           -1.5            5.3          -15.3           0.19           77.8
+156.      2.2           -0.6            6.1          -12.8           0.00           11.2
+168.      8.0           -2.3            3.7          -14.1           0.00           16.3
+180.      1.7           -2.5            1.1          -14.1           0.06           17.7
+192.      3.6           -8.0            0.5          -15.3           0.12           21.8

Texted I am sure is grammatically correct.

Yep icing def looks like a problem. Something to keep an eye on as we head into the week. If this event does transpire there will be a thin line between ice and snow.

[TexasMetBlake]

Looking at it the 18z gfs, it appears as though the moisture will be closer to the coast where icing could be more of a problem. The northern sections of SE TX may be moisture starved but any thing that might fall would probably be snow...

[sambucol]

Looking at it the 18z gfs, it appears as though the moisture will be closer to the coast where icing could be more of a problem. The northern sections of SE TX may be moisture starved but any thing that might fall would probably be snow...

What kind of temps is the 18z gfs suggesting? The reason I'm asking is to get an idea of what kind, if any, preparations I will need to make this weekend. If we do have an icing event, it wouldn't be a bad idea to make sure our generators are ready.

[wxman57]

What kind of temps is the 18z gfs suggesting? The reason I'm asking is to get an idea of what kind, if any, preparations I will need to make this weekend. If we do have an icing event, it wouldn't be a bad idea to make sure our generators are ready.

Nothing too extreme, just temps holding near freezing all day Feb 1-2 with lots of moisture. But I wouldn't take this run too literally. There are signs that the airmass could be a good bit colder.

[sambucol]

Nothing too extreme, just temps holding near freezing all day Feb 1-2 with lots of moisture. But I wouldn't take this run too literally. There are signs that the airmass could be a good bit colder.

Thanks. For you to say that the airmass could be a good bit colder has me taking notice. I'm guessing the best thing to do is plan on doing preps around the house next weekend for some icing. It sounds like the cold air is a done deal, and the moisture will probably be a part of it.

Still hope we get snow!

[biggerbyte]

I hope no one is getting their hopes up over this "event".

[sambucol]

I hope no one is getting their hopes up over this "event".

There's nothing wrong with hoping! That said, my schedule is extremely busy this week, so I'm trying to figure out when, if needed, to do some things around the house to prepare for potential icing or extreme cold.

[jabcwb2]

At what temp will snow fall?

[biggerbyte]

I hope no one is getting their hopes up over this "event".

There's nothing wrong with hoping! That said, my schedule is extremely busy this week, so I'm trying to figure out when, if needed, to do some things around the house to prepare for potential icing or extreme cold.

I certainly agree with everything you said. Even though we are not sure yet, just like with having a hurrican in the Gulf, if would be smart to prepare. There is potential for things to go either way, folks, and we have been burned by the models this entire winter. Hope for the best luck this time, and prepare for it, as there could be some icing issues if this develops. However, I strongly suggest everyone not have any expectations.

[seanatsk]

At what temp will snow fall?

Ground temperatures are really unimprotant. The true indicator of snow fall is the right type of air column. There has to be a freezing and a warm layer to let it re-freeze. I have seen it snow at 40 degrees but it didn't stick. Wxman has a formula for the type of surface temp that is more conducive for snow fall.

[TexasMetBlake]

At what temp will snow fall?

Ground temperatures are really unimprotant. The true indicator of snow fall is the right type of air column. There has to be a freezing and a warm layer to let it re-freeze. I have seen it snow at 40 degrees but it didn't stick. Wxman has a formula for the type of surface temp that is more conducive for snow fall.

This is not correct. If there was a warm layer, the snowflake would transform into a raindrop if it fell into a warm column and then refreeze in the form of a rain drop. We call this sleet. You are correct about ground temps---to a point. It has to be cold but if the snow falls hard enough, it can snow with temps in the 40s. But that is very rare. Normally at 35 or 36 degrees, you can get a good snowfall. We've seen that here in Houston several times. However, the entire column from just above the surface to 850 must be freezing.

[sleetstorm]

What altitude is 850 in feet, Candy Cane, 10,000 ft.? What temperature would the air have to be in the middle and upper layers of the atmosphere, specifically the troposphere, for dry fluffy snow to develop & reach ground level, 20's/10's?

[Andrew]

What altitude is 850 in feet, Candy Cane, 10,000 ft.?

850mb=5000ft

[TexasMetBlake]

What altitude is 850 in feet, Candy Cane, 10,000 ft.?

850 mb is approximately 5,000 ft. That's why out west when we see these big high pressure systems come down and you look at the 850 temps, those translate to surface temps for places like Denver.

[sleetstorm]

Okay, thank you for that altitude map explication, Andrew and that explication, Candy Cane.