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

[Extremeweatherguy]

Current conditions at my house in Spring:

Temp = 45.9F
Sky = Overcast with mist
Wind = Breezy out of the north

**I have dropped 1.2F in the last 30 minutes**

[wxman22]

The new NAM MOS TEMPS:

[42 as a high tommorow
30 the low tommorow night
34 for a HIGH!! on Sunday
30 Sundat night...]

[vbhoutex]

If the temps don't start moving down(ie the colder air obviously to our NW)soon we aren't even going to get into the 30's tonight. Looking at the precip types it is obvious where the colder temps are and they are still quite a ways to our NW. Doesn't mean they can't push on in here tonight, but they have a ways to go especially with the thick cloud cover we have.

[Extremeweatherguy]

Wow. If that 30-34-30 verifies then we may see a significant icing event down this way. Also...that 42F tomorrow will probably occur in the morning..I expect most of the day to be falling through the 30s.

[Extremeweatherguy]

If the temps don't start moving down(ie the colder air obviously to our NW)soon we aren't even going to get into the 30's tonight. Looking at the precip types it is obvious where the colder temps are and they are still quite a ways to our NW. Doesn't mean they can't push on in here tonight, but they have a ways to go especially with the thick cloud cover we have.

I think they will. The lower dewpoints are slowly trying to ooze into the area and as they lower, our temperatures will lower too. Even if not in the upper 30s tomorrow morning...I still think that we fall into the 30s during the day...the coldest day now looks like it may be Sunday when we may struggle to get out of the lower to middle 30s!

ALSO: As of 10pm, the temperature at Hooks has fallen to 46F (1F lower than at 9pm. Also..the dew point has dropped 1F down to 43F). IAH however is still at 49F...but they too have seen their dewpoint fall to 43F and if they see any rain at IAH the temp. should quickly fall (due to evap. cooling) to the middle 40s. I predict lows tonight will be from the upper 30s to lower 40s just as expected.

[Extremeweatherguy]

Here is a good page to look at the dewpoints...the area of drier air has been slowly oozing toward us over the last few hours and dewpoints have already fallen a good 4F since earlier this evening.

[wxman22]

WOW 0z GFS has took a even more dramatic change look how far south the 2m freezing line is now (much further south than previouse runs)

[Extremeweatherguy]

Here is a summary of when the ETA (NAM) Is expecting winter weather.

-It has light freezing rain in the area from 6Z Sunday (Saturday evening) until 12Z Monday (Monday morning)...that is a one and half day stretch!

-It shows a brief window for a little sleet overnight Saturday into Sunday morning.

Basically it looks like a light freezing rain mixed with rain and sleet event for Houston if the ETA is right. It would also be very cold and the ETA drops us into the 30s tomorrow afternoon and does not raise us out of the 30s until early Monday Afternoon (2 full days). It also brings us down to as low as 30F at times meaning that some ice accumulation is possible. Looking at this scenario...IF the ETA was right then I think our area could be looking at some ice accumulations of a glaze to 1/10th of an inch...in fact, I would not be surprised if one or two places in SE Texas saw 0.25"+ of ice. Now this, of course, is IF the 0Z ETA is correct. All I know is that I will be watching VERY closely tomorrow to see what happens with the models, forecasts, and weather conditions!

[Extremeweatherguy]

WOW 0z GFS has took a even more dramatic change look how far south the 2m freezing line is now (much further south than previouse runs)

All these trends are very good for Houston. At this point I will be quite surprised if I don't see some ice out of this.

[wxman22]

Look at the precip type of the new 0z GFS :


http://www.rap.ucar.edu/weather/model/d ... hr030hr036

[Furious George]

NWS no longer predicting frz rain for the Conroe area - they seemed to have backtracked a little. What was looking like quite promising last night is now a lot more of a question for those near Houston.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
529 AM CST SAT FEB 18 2006

.DISCUSSION...
UPPER TROUGH STRETCHES FROM OREGON TO HUDSONS BAY WITH FAIRLY
STRONG RIDGING OVER THE GULF THIS MORNING. DOWN LOW THE ARCTIC
AIRMASS SPILLING DOWN INTO OK/TX WITH THE 850 AND 925MB FRONTS
ALMOST TO DFW AT 10Z. VERY SHALLOW COLD AIRMASS IN PLACE OVER
SETX THIS MORNING WITH TEMPERATURES LOCALLY IN THE LOWER TO MID
40S WITH NORTHERLY WINDS OF 5 TO 15 MPH. THE UPPER RIDGE OVER THE
GULF WILL WEAKEN AND FLATTEN THROUGH MONDAY ALLOWING THE UPPER
TROUGH TO SAG FARTHER SOUTH AND SOME OF THE COLDER AIR TO PUSH
SOUTH INTO SETX. LOW LEVEL MOISTURE CONTINUE TO RIDE UP AND OVER
THE COLD AIRMASS PRODUCING A THICK CLOUD LAYER. THIS SATURATED AIR
WILL GET THE SQUEEZE AS A SERIES OF VERY VERY WEAK SHORT WAVES
RIPPLES OVERHEAD IN THE SOUTHWESTERLY FLOW ALOFT. SO IT LOOKS AS
THOUGH WE WILL HAVE CLOUDY CONDITIONS WITH PERIODS OF LIGHT RAIN
THROUGH SUNDAY. THIS POSES A PROBLEM COME 06-14Z SUNDAY TIME FRAME
AS COLDER AND DRIER AIR FILTERS IN TO THE NORTHERN ZONES.
SOUNDINGS INDICATE THAT RAIN MIGHT BE CAPABLE OF SWITCHING OVER TO
FREEZING RAIN FOR A FEW HOURS OVER THESE NORTHERN ZONES BUT
CONFIDENCE IS LOW THAT WE WILL GET THE RAIN COINCIDENT WITH THE
COLDER TEMPERATURES. HAVE PARED BACK THE SOUTHERN EXTENT OF THE
FREEZING RAIN FROM PREVIOUS PACKAGE. GIVEN THE LOW CONFIDENCE WILL
NOT ISSUE A WINTER WEATHER ADVISORY AT THIS TIME AND WILL LET THE
DAYSHIFT OR FOLLOWING EVENING SHIFT ISSUE ONE IF IT ACTUALLY
BECOMES NECESSARY. GFS AND ECMWF IN DECENT AGREEMENT FOR PERIOD
BEYOND MONDAY SO HAVE MADE SOME TWEAKS THERE FOR A LITTLE WARMER
AFTERNOONS AS HIGH SHIFTS EAST AND PRESSURES FALL OVER WEST TEXAS
AND SOUTHERN ROCKIES. RAIN CHANCES GO BACK UP AS JET ENTRANCE
REGION MOVES INTO THE REGION WEDNESDAY AND MOISTURE SURGES BACK
WITH INCREASING INSTABILITY. THEN PACIFIC FRONT MOVES THROUGH
THURSDAY WITH A CONTINENTAL AIRMASS ON ITS HEELS EARLY FRIDAY
MAKING FOR A COOL WEEKEND

[wxman22]

NWS no longer predicting frz rain for the Conroe area - they seemed to have backtracked a little. What was looking like quite promising last night is now a lot more of a question for those near Houston.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
529 AM CST SAT FEB 18 2006

.DISCUSSION...
UPPER TROUGH STRETCHES FROM OREGON TO HUDSONS BAY WITH FAIRLY
STRONG RIDGING OVER THE GULF THIS MORNING. DOWN LOW THE ARCTIC
AIRMASS SPILLING DOWN INTO OK/TX WITH THE 850 AND 925MB FRONTS
ALMOST TO DFW AT 10Z. VERY SHALLOW COLD AIRMASS IN PLACE OVER
SETX THIS MORNING WITH TEMPERATURES LOCALLY IN THE LOWER TO MID
40S WITH NORTHERLY WINDS OF 5 TO 15 MPH. THE UPPER RIDGE OVER THE
GULF WILL WEAKEN AND FLATTEN THROUGH MONDAY ALLOWING THE UPPER
TROUGH TO SAG FARTHER SOUTH AND SOME OF THE COLDER AIR TO PUSH
SOUTH INTO SETX. LOW LEVEL MOISTURE CONTINUE TO RIDE UP AND OVER
THE COLD AIRMASS PRODUCING A THICK CLOUD LAYER. THIS SATURATED AIR
WILL GET THE SQUEEZE AS A SERIES OF VERY VERY WEAK SHORT WAVES
RIPPLES OVERHEAD IN THE SOUTHWESTERLY FLOW ALOFT. SO IT LOOKS AS
THOUGH WE WILL HAVE CLOUDY CONDITIONS WITH PERIODS OF LIGHT RAIN
THROUGH SUNDAY. THIS POSES A PROBLEM COME 06-14Z SUNDAY TIME FRAME
AS COLDER AND DRIER AIR FILTERS IN TO THE NORTHERN ZONES.
SOUNDINGS INDICATE THAT RAIN MIGHT BE CAPABLE OF SWITCHING OVER TO
FREEZING RAIN FOR A FEW HOURS OVER THESE NORTHERN ZONES BUT
CONFIDENCE IS LOW THAT WE WILL GET THE RAIN COINCIDENT WITH THE
COLDER TEMPERATURES. HAVE PARED BACK THE SOUTHERN EXTENT OF THE
FREEZING RAIN FROM PREVIOUS PACKAGE. GIVEN THE LOW CONFIDENCE WILL
NOT ISSUE A WINTER WEATHER ADVISORY AT THIS TIME AND WILL LET THE
DAYSHIFT OR FOLLOWING EVENING SHIFT ISSUE ONE IF IT ACTUALLY
BECOMES NECESSARY. GFS AND ECMWF IN DECENT AGREEMENT FOR PERIOD
BEYOND MONDAY SO HAVE MADE SOME TWEAKS THERE FOR A LITTLE WARMER
AFTERNOONS AS HIGH SHIFTS EAST AND PRESSURES FALL OVER WEST TEXAS
AND SOUTHERN ROCKIES. RAIN CHANCES GO BACK UP AS JET ENTRANCE
REGION MOVES INTO THE REGION WEDNESDAY AND MOISTURE SURGES BACK
WITH INCREASING INSTABILITY. THEN PACIFIC FRONT MOVES THROUGH
THURSDAY WITH A CONTINENTAL AIRMASS ON ITS HEELS EARLY FRIDAY
MAKING FOR A COOL WEEKEND

Im not gonna buy that yet ill need to see a few more model runs remember in December when Austin & Dallas had that Ice storm and the NWS was forcasting only freezing temps in the Northern counties & then later in the the nights discussion they changed the forcast and put freezing temps in the central counties to (as the temps were colder than thought....)

[Furious George]

This is going to depend on the magnitude of the cold/dry air surge that is on its way. At this point, I would not expect frz precip for the greater Houston area - but it's still worth keeping an eye on. Temps to the north of us (BCS, Waco, Dallas) about par with forecast so far.

[Mattie]

Nothing going on in North Texas - - - just a few frozen patches on the BBQ grills . . . But it's still chilly enough (26 degrees right now) to build a huge roaring fire.

[Extremeweatherguy]

In Houston dewpoints and temps. are slowly falling this morning. Currently Hooks airport is 42F with a dewpoint of 38F. I think the chance of frozen precip. all depends on what goes on today. We are only 10F above the freezing mark at Hooks, so it will not take a lot to get us there...we just need some lower dew points! The good news is that last night at 10pm the dewpoint was 45F, and now at 9am it is 38F...so we are slowly lowering them...hopefully we can pick up the pace today.

ALSO: I want to let everyone know that weather.com AND accuweather.com are both forecasting a low of 32F in Spring tonight.

[Extremeweatherguy]

Also...I forgot to mention this...but we also need to remember that the morning NWS staff and the afternoon NWS staff are different. The morning staff may not be seeing something that they saw in the afternoon staff.

[Extremeweatherguy]

Here is a look at a few models this morning:

http://www.wunderground.com/modelmaps/m ... &domain=US
^^ETA still looks promising tomorrow morning for north Houston^^

http://www.wunderground.com/modelmaps/m ... &domain=US
^^THe GFS also looks promising^^

So it is not like the models have backed off...in fact they are still saying "game on for winter weather!"

[wxman22]

Hazardous Weather Outlook
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
700 AM CST SAT FEB 18 2006

TXZ163-164-176>179-195>200-210>214-226-227-235>238-191300-
AUSTIN-BRAZORIA-BRAZOS-BURLESON-CHAMBERS-COLORADO-FORT BEND-
GALVESTON-GRIMES-HARRIS-HOUSTON-JACKSON-LIBERTY-MADISON-MATAGORDA-
MONTGOMERY-POLK-SAN JACINTO-TRINITY-WALKER-WALLER-WASHINGTON-
WHARTON-
700 AM CST SAT FEB 18 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST
TEXAS.

.DAY ONE...TODAY AND TONIGHT
NEAR FREEZING TEMPERATURES WILL OCCUR LATE TONIGHT AND EARLY
SUNDAY MORNING ALONG AND NORTH OF A LINE FROM CALDWELL TO CROCKETT.
LIGHT RAIN MAY BRIEFLY MIX WITH LIGHT FREEZING RAIN OVER THESE
LOCATIONS AFTER MIDNIGHT AND CONTINUE UNTIL 7 OR 8 AM SUNDAY. THE
ROADS MAY BE TOO WARM FOR THIS TO ACCUMULATE BUT AUTOMOBILES AND EXPOSED
METAL OBJECTS MAY HAVE VERY LIGHT ACCUMULATIONS...AT THIS TIME
THE CHANCE OF FREEZING RAIN IS SLIGHT...HOWEVER IF THE VERY COLD
AIR OVER THE SOUTHERN PLAINS PUSHES A BIT FURTHER SOUTHWARD THE
CHANCES OF FREEZING RAIN WILL INCREASE. A WINTER WEATHER ADVISORY
MAY BE REQUIRED FOR SATURDAY NIGHT AND SUNDAY MORNING.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

$$

[Extremeweatherguy]

Yeah see the HWO says that if the very cold air in the southern plains pushes southward that the frz. rain chances will increases for lots of the area....I think that is what the afternoon shift was expecting yesterday. The morning shift looks like they are holding back until they are confident enough that it will happen.

[Extremeweatherguy]

Current (9:19am) Backyard conditions:

Temp = 40.6F
Sky = Overcast with drizzle
Winds = Breezy out of the north