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

[Extremeweatherguy]

0Z GFS seems to show a possible "slight (10-20%)" chance of wintry precip. Saturday morning as well...

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _024.shtml
^^24 hrs.^^

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _030.shtml
^^30 hrs.^^

Not anywhere close to Houston...

Actually, Houston is in the light green area and with very dry air, and 850mb temps. near 0C....that may be enough to give Houston a few flurries on Saturday morning. The NAM is even more agressive with precip. in Houston on Sat. morning. At this point though...I would say that the chances of a flurry or two are only 10-15%.

[Tyler]

Well Extreme, now that the GFS shows 25 degrees, lets see if the NWS takes temps that low. If it wasn't for the NAM and its idiotic temp forecast, it would be a sure bet that they would lower them. However, now they will be like "well, the NAM says only 30, and since we're warm biased, lets go with that...".

[Tyler]

Also, all those ridiculous forecasts for temperatures from the news stations around town have GOT to go. Only 30 degrees, HA!

[Extremeweatherguy]

Well Extreme, now that the GFS shows 25 degrees, lets see if the NWS takes temps that low. If it wasn't for the NAM and its idiotic temp forecast, it would be a sure bet that they would lower them. However, now they will be like "well, the NAM says only 30, and since we're warm biased, lets go with that...".

yeah, another thing is...the surface temp. forecasts from the models seem to bust with every arctic outbreak I have ever seen (especially in the south, near a water source). I mean come on, the NAM shows -8C to -9C 850mb temps...but only 30F? Sounds like an error to me. The GFS and NGM may be more in line with their 25 degree predictions though.

[Extremeweatherguy]

wow. the NGM has by far the best look for winter weather in Houston. Look at those 850mb temps. combined with the precip. at 30 hrs. out...interesting to say the least:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _030.shtml

I hope that all these small chances of a winter possibilty on the models tonight become a trend tomorrow.

[Tyler]

wow. the NGM has by far the best look for winter weather in Houston. Look at those 850mb temps. combined with the precip. at 30 hrs. out...interesting to say the least:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _030.shtml

I hope that all these small chances of a winter possibilty on the models tonight become a trend tomorrow.

Wow!

[AL Chili Pepper]

Tomorrow will be interesting as more of the details come together. Who will change their mind first? NWS Mobile or NWS Jackson/Birmingham/New Orleans. No word of *now in the Mobile forecast discussion, with the others talking of a chance of snow/snow showers nearly to the coast. Good stuff to wake up to in the morning.

[Ivanhater]

Tomorrow will be interesting as more of the details come together. Who will change their mind first? NWS Mobile or NWS Jackson/Birmingham/New Orleans. No word of *now in the Mobile forecast discussion, with the others talking of a chance of snow/snow showers nearly to the coast. Good stuff to wake up to in the morning.

interesting!

[Huckster]

Hmm, I'm consumed with work and family issues right now, so I haven't had as much time as lately to dedicate to the weather. That being said, with all that is being said here, WHY has the forecast low for Baton Rouge for Sunday morning been raised from 26 to 30 degrees? Seems like there's talk of it being cold cold cold in Houston but the majority of the cold air actually going east of there. If that happens, how could it end up warmer in Baton Rouge than in Houston?

[weatherlover427]

To compare the 2 models, I did a zoom on the surface temps at both 48 and 60 hrs using the GFS and NAM (aka the AVN and ETA, as the site that I used still refers to them as). Here are the results:

GFS 60 HOURS:



NAM 60 HOURS:



You can see the drastic temperature differences for areas such as Houston, San Antonio, Austin, etc. using the colder ETA versus the warmer GFS.

Now here is Saturday afternoon:

GFS 48 HOURS:



versus

NAM 48 HOURS:



Note how much more similar the 2 models are at this time frame. They show nearly identical surface temps for mostly everywhere in the South Saturday afternoon.

[southerngale]

Ya, Dr. Neil has this situation pegged right now... News stations in Houston have ALWAYS been scared to put 20s in the forecast. I don't know why. The lowest they will go is 30, before they finally give in at the last minute...

KFDM in Beaumont has shown 20's for Sunday and Monday mornings since Wednesday afternoon.

[Brent]

Also, all those ridiculous forecasts for temperatures from the news stations around town have GOT to go. Only 30 degrees, HA!

30 degrees for what airport?

I'm going to *guess* 27-28 for IAH, 30-31 for Hobby and 33 for Galveston.

[wxman22]

Heres a link to the latest european model run:

http://weather.cod.edu/forecast/

[wxman22]

Heres the latest discussion from the NWS in Houston:AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
317 AM CST FRI FEB 10 2006

.DISCUSSION...
AT 08Z...A DEVELOPING WARM FRONT EXTENDED FROM JUST SOUTH OF ALICE
TO BUOY 019 AND THEN EASTWARD OVER THE GULF. AN AREA OF LOW
PRESSURE WAS DEVELOPING OVER SOUTHWEST TEXAS AND A COLD FRONT WAS
PUSHING SOUTH...EXTENDING FROM OKLAHOMA CITY TO JUST SOUTH OF
LUBBOCK.

MOISTURE LEVELS ARE INCREASING ACROSS THE AREA. GPS SATELLITE
SHOWS PW`S NEAR 1.2 INCHES NEAR CRP AND 0.90 INCHES NEAR CLL. PW`S
ARE PROGGED TO CLIMB TO AROUND 1.5 INCHES EARLY THIS AFTERNOON.
ISENTROPIC UPGLIDE HAS PRODUCED A LARGE SWATH OF LIGHT RAIN OVER
THE NORTHERN 2/3RDS OF TEXAS. AN UPPER LOW OVER NEW MEXICO WILL
WEAKEN AS IT PUSHES EAST TODAY. AS THIS FEATURE APPROACHES...
SHOWERS WILL TRANSITION TO THUNDERSTORMS DURING THE MID-MORNING.
THE COLD FRONT OVER NORTH TEXAS WILL MOVE RAPIDLY ACROSS TEXAS AND
SHOULD BE CLEARING THE COAST AROUND 00Z. PRECIP SHOULD INCREASE
RAPIDLY BETWEEN 15-18Z...PEAKING BETWEEN 16-21Z AND END QUICKLY
FROM WEST TO EAST. THE PROGRESSIVE NATURE OF THIS SYSTEM SHOULD
PRECLUDE HEAVY RAIN AND FEEL PREVIOUS FORECASTER QPF ESTIMATES
(0.5 TO 1.0 INCHES WITH ISOLATED 2-3 INCHES) LOOKS ON THE MARK.

AM CONCERNED ABOUT SEVERE POTENTIAL TODAY ALONG THE COASTAL
COUNTIES. SPEED AND DIRECTIONAL SHEAR ARE QUITE IMPRESSIVE WITH
HELICITIES NEAR 300. 850 MB WINDS ARE FORECAST TO INCREASE TO
BETWEEN 40 AND 50 KNOTS. THE AREA WILL LIE IN A 250 MB JET
COUPLET. WIDESPREAD CLOUDINESS SHOULD LIMIT HEATING/INSTABILITY
AND REDUCE THE SEVERE THREAT. THE WILD CARD IS THE DEVELOPING WARM
FRONT ALONG THE COAST. THIS FEATURE IS PROGGED TO REMAIN OFFSHORE
BUT SFC DEW POINTS ARE ALREADY CLIMBING INTO THE LOWER 60S ALONG
THE MIDDLE COAST. CONFIDENCE IS LOW...BUT FEEL IT IS BEST TO
MENTION SOME POSSIBILITY OF SEVERE WEATHER IN THE FIRST TWO TIERS
OF COUNTIES NEAR THE COAST IN CASE THE WARM FRONT MOVES ONSHORE.
THE PRIMARY SEVERE WEATHER HAZARD WILL BE WIND DAMAGE AND ISOLATED
TORNADOES.

MUCH COLDER WEATHER ON TAP FOR THE WEEKEND AS CANADIAN HIGH
PRESSURE SETTLES OVER THE REGION. WET GROUND AND MIXING FROM WINDS
WILL KEEP TEMPS FROM FALLING TOO FAR SATURDAY MORNING. COLD AIR
ADVECTION AND STRONG WINDS (MIXING) WILL KEEP SATURDAY CHILLY.
SUNDAY MORNING LOOKS TO BE THE COLDEST NIGHT AS WINDS DECOUPLE AND
THE WET GROUND HAS A CHANCE TO DRY.

SATURDAY-TUESDAY LOOK DRY AS HIGH PRESSURE REMAINS IN CONTROL. ANOTHER
WEAK S/WV WILL CROSS THE AREA ON WEDNESDAY AND HAVE ADDED A SLIGHT
CHANCE OVER THE NORTH CLOSEST TO THE S/WV. WEAK RIDGING BUILDS IN
TO THE AREA THURSDAY BEFORE ANOTHER S/WV APPROACHES ON FRIDAY.

&&

[Portastorm]

Uh-oh!

NWS Austin/San Antonio now says a low for us (Austin) Saturday night of 22!!

[Tyler]

Houston's forecast of mid 50's saturday will likely bust by 8 degrees.

[Extremeweatherguy]

well...the NWS has doen good and bad this morning in our area. Officially at my house, they are now forecasting a low of 26-27F. At IAH, however, the low is forecasted at about 28F, and downtown they are forecasting 31F. Also...they have been mentioning PERFECT radiational cooling all week, and then this morning they go and put 5-15mph winds in the forecast for Sat. night? sounds like they might be using that as an excuse for why they are not forecasting cooler. hmmm. Also, Saturday's temp. has been risin to 54F for a high...I believe that will be way too warm for a day with such strong CAA and breezy north winds...not to forget also...a cloudy morning. Looks like the front is in the vicinity of Abilene and Witchita falls right now and temps. have been falling a good 10+ degrees behind it...but since it should strengthen as it comes southward...by the time it gets to us; I would expect a 10-20 degree drop. Should be exciting. There is also a little change over to snow taking place on the back edge of the precip in parts of the southern panhandle and oklahoma. As for snow in Houston...I would say chances of slim at best. I am still hopeful for the cold next weekend, as a latest quote from JB says, "Texas shot in and out, then big problems next week NO changes in forecast lows form earlier idea, here or in Florida." Those lows he is talking about are 26 in Orlando and 26 in Mcallen (which he still feels could happen). If they got that cold down in Mcallen...then we in Houston would probably see our coldest temps. since 1996 when IAH hit 21F (19F at Hooks). Fun weather week ahead..

[Extremeweatherguy]

The weird thing about Sat night too is that they have a forecast of 5-15mph winds in the forecast, but yet the AFD says this...

SUNDAY MORNING LOOKS TO BE THE COLDEST NIGHT AS WINDS DECOUPLE AND
THE WET GROUND HAS A CHANCE TO DRY.

[Extremeweatherguy]

Below are a few models hinting at the possibility of a flurry or two:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _024.shtml
^^NAM 24 hrs.^^

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _024.shtml
^^GFS 24 hrs.^^

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _030.shtml
^^NGM 30 hrs.^^

I would say that the chances right now are 10% for a flurry. Hey that's at least a "Chance" right?

[ocracoke]

Also...they have been mentioning PERFECT radiational cooling all week, and then this morning they go and put 5-15mph winds in the forecast for Sat. night? sounds like they might be using that as an excuse for why they are not forecasting cooler. hmmm.

All this NWS bashing is starting to get irritating. Why would they use that as an excuse? What overall purpose does that serve? If you guys would analyse something in addition to 850 mb temperatures and the strength of the surface ridge axis, you could see why their forecast includes 15 mph wind for Saturday night. High pressure is still building in at that time, while cold air advection remains continuous, with winds backing towards the NW. By early Sunday morning, high pressure has ridged in and slackened the pressure gradient enough so that the surface might very well decouple.