January: Seasonal Temps To End The Month

[MontgomeryCoWx]

No. JB clearly said I-10 in Texas.

Yes, that's correct, most likely I-10 to the west of the Houston area probably close to the hill country. That's still Texas.

I still expect to see Montgomery and possible the Northern portions of Harris County to be under a Winter Weather Advisory mid wek.

[srainhoutx]

While the GFS is somewhat slower to close off the 500mb upper low and a tad slower or less progressive than the WRF/NMM (NAM) suggested. That model (GFS) is suggesting a wave of surface low pressure develops along Coastal Texas and very cold air aloft slowly treks E across Central Texas. The GFS is drier at the 700mb level, but as we have seen the models are not handling features too well with the noisy sub tropical jet and embedded short wave activity.

[wxman57]

I saw that JB said snow all the way down to I-10. Is he smoking crack of what????!!!

I thought he may be talking about areas to our east (MS/AL and maybe southern GA), as the colder air will be over there next week.

[JackCruz]

Was looking at Accuweather's hourly forecast for Tuesday/Wednesday (I think...it's was early this morning) and I saw 33/34 degrees for Cypress/Houston with rain..wouldn't that be AT LEAST sleet if not snow flurries? I'm just gonna make a wild, crazy, immature, and uneducated guess here....maybe a snow flurry or two is possible...not likely but the potential is there

[sambucol]

From Joe B: "@BigJoeBastardi: May see it snow all the way into I-10 corridor of Texas Thur or Fri. Money in bank sw system will be heard from. to e coast."

"@BigJoeBastardi: Gotta love it! GFS has nice wintery surprise brewing out of money in the bank system for the deep south. Could even snow on Duck Dynasty."

[JackCruz]

Sitting at 39 degrees here in cypress and it feels like 28. I better enjoy this before the heat returns!

[wxman57]

Was looking at Accuweather's hourly forecast for Tuesday/Wednesday (I think...it's was early this morning) and I saw 33/34 degrees for Cypress/Houston with rain..wouldn't that be AT LEAST sleet if not snow flurries? I'm just gonna make a wild, crazy, immature, and uneducated guess here....maybe a snow flurry or two is possible...not likely but the potential is there

Surface temperature near, at, or below freezing with precipitation does not guarantee snow flurries. What matters is the air aloft. In this case, the GFS is forecasting that the coldest air is at the surface. The temperature rises sharply above the surface, up to around 50 degrees at 5000 ft up. The temperature doesn't drop to freezing until nearly 17,000 ft above the surface. All the precip on Tuesday would be falling from air that's well above freezing. Same for Wednesday, though the air aloft is a bit colder (low to mid 40s vs. 50). All 33/34 degrees and precip guarantees is miserable weather for us Tue/Wed.

[srainhoutx]

HGX is giving a few 'hints' as to what they are thinking and should make for some interesting updates later today into tomorrow. FYI: 38 degrees here in NW Harris County.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
955 AM CST MON JAN 14 2013

.UPDATE...
UPPER TROUGH IS HUNG UP OUT WEST...WITH EASTERN TEXAS FALLING
WITHIN THE MORE LIFT-CONDUCIVE RIGHT REAR QUAD OF THE POLAR JET
STREAM. LOWER LEVEL COLD AIR ADVECTION...WITH EFFICIENT UPGLIDE
OF MOIST MILD PACIFIC MID-LEVEL AIR OVER THIS LOWER COLD DOME...
MAKING FOR A COLD AND OVERCAST MORNING WITH PERIODIC SHOWERS.
THIS NASTY WEATHER WILL LINGER ON THROUGH MID-WEEK. THE SYNOPTIC
PATTERN OF A QUASI-STATIONARY WESTERN U.S SW-TO-NE STRETCHED MID-
UPPER LEVEL TROUGH PLACING THE JET STREAM ACROSS WESTERN TEXAS...
WITH LOWER LEVEL SATURATION (SUB-700 MB) AND NEAR SURFACE
TEMPERATURES FALLING TO NEAR (OR SLIGHTLY BELOW) FREEZING...THERE
WILL BE A CHANCE FOR A WINTRY MIX OF RAIN/SLEET OVER THE NEXT
COUPLE OF MORNINGS ACROSS THE NORTHERN CWA. THERE WILL BE MORE ON
THIS IN THE AFTERNOON PACKAGE CONCERNING TIMING AND PRECIPITATION
TYPE. IN THE MEANTIME...THE NEXT COUPLE OF AFTERNOONS WILL HAVE A
HARD TIME WARMING INTO THE LOWER TO MIDDLE 40S FROM THE LOWER TO
MIDDLE 30S (COASTAL LOWER 40S) AS MOST OF THE DAY WILL BE MOSTLY
CLOUDY WITH PERIODICALLY-PASSING PESKY LIGHT SHOWERS AND/OR DRIZZLE
(MIST).

[srainhoutx]

The 12Z CMC (Canadian) is somewhat similar to the GFS solution although a bit 'wetter' at the 700mb level. The air aloft is rather chilly within the 500mb vort and IF the Euro should trend to the closed cold core upper low that the 12Z operational guidance has suggested so far, we will need to closely monitor the late Tuesday evening into Thursday morning time frame.

[MontgomeryCoWx]

Wednesday off work wouldn't be bad.

[srainhoutx]

HPC Model Diagnostic Discussion excluding the Euro through the 12Z suite of operational guidance:

...SHORTWAVE ENERGY DIVING FROM THE GREAT BASIN INTO THE BASE OF
THE LARGE SCALE WESTERN U.S. THROUGH TUE...
...CLOSED LOW DEVELOPING OVER THE SOUTHERN PLAINS TUE THROUGH
THU...

PREFERENCE: 12Z GFS/00Z ECMWF BLEND
CONFIDENCE: BELOW AVERAGE

THE 12Z NAM IS SLOWER THAN THE GLOBAL MDL CONSENSUS AND IS A DEEP
OUTLIER WITH THE ENERGY AMPLIFYING OVER THE SRN PLAINS AND ITS
CLSD LOW EVOLUTION INTO THE LWR MS/TN VLYS THROUGH THU. EVERY
OTHER MDL SUGGESTS A MORE MODEST CLSD LOW THAT WILL DEVELOP AND
THEN SHEAR EWD THROUGH THE SRN PLAINS AND INTO THE GULF COAST
STATES. THE 12Z GEM GLOBAL IS THE SLOWEST...WITH THE 12Z UKMET THE
FASTEST AND MOST SHEARED. THE 06Z GFS AND 00Z ECMWF BOTH CLUSTER
RELATIVELY WELL WITH A MORE MODEST SHEARING OF THE ENERGY INTO THE
GULF COAST STATES. THE 12Z GFS IS JUST A TAD STRONGER. THESE MDLS
SPLIT THE DIFF BETWEEN THE SLOW GEM GLOBAL AND FAST UKMET. THE 00Z
ECENS MEAN SUPPORTS THE 12Z GFS/00Z ECMWF OVERALL...WITH THE 06Z
GEFS MEAN ACTUALLY NOTABLY SLOWER AND KEEPING ENERGY TUCKED
FARTHER WEST OVER THE SRN PLAINS FOR A LONGER PD OF TIME. WILL
FAVOR A 12Z GFS/00Z ECMWF BLEND...WITH LIMITED CONFIDENCE GIVEN
THE OVERALL GLOBAL MDL SPREAD.

[srainhoutx]

The 12Z Euro continues the trends suggested by the other global and shorter range operational guidance but is a bit progressive or faster in moving the 500mb low across Texas. It is noteworthy that the Euro does suggest a bit more moisture and colder surface temps across Louisiana. The Euro also develops a wave of low pressure along the Texas Coast and moves that surface low ENE toward Southern Louisiana.

[srainhoutx]

A brief note on the strong Polar front expected early next week. The 12Z Euro has flipped back to a very cold solution suggesting a 1050mb+ Arctic High Pressure dropping S from Canada into the Plains and a bit less of a 'glancing' push of the colder air off to the East.

[wxman57]

The 12Z Euro doesn't really drive any extreme cold to Texas, though. 850mb temps well above freezing next week. Lows in the upper 20s to 30 a fair bet.

[MontgomeryCoWx]

My hometown of Longview had freezing rain and sleet this morning. Had a white Christmas and I expect it to see another bout of ice/snow this week (maybe 2 bouts).

[srainhoutx]

The 12Z Euro doesn't really drive any extreme cold to Texas, though. 850mb temps well above freezing next week. Lows in the upper 20s to 30 a fair bet.

The 12Z Euro is much 'colder' than the 00Z of that very model suggested... My hunch is the operational guidance still hasn't firgured out how to handle the upper air pattern and just how cold the surface temps will actually be. The 12Z GEFS also trended colder as well.

00Z Euro:

12Z GEFS:

[Portastorm]

I suppose it will depend a lot on the orientation of the West Coast ridge early next week. A sharper, more pronounced ridge will likely bring that polar air south. Hard to image a 1050mb high coming south out of Montana and not diving south-southeast ... but if that ridging is far enough east, I suppose it could.

[wxman57]

Just comparing the 00Z Euro and 12Z Euro's 850mb temps over SE TX, the 00Z run had temps down to +5C across Houston, while the 12Z run has the coldest temps at 850mb (5000ft) only down to +7C. That's not particularly cold. Of course, much will depend on the character of the airmass that moves southward next week. Arctic air, if any is involved, tends to be quite shallow, not even extending to 5000ft down here. So the 850mb temp may not be a good estimate of surface temps. Regardless, I'm not seeing any "historic cold" as some have mentioned over the past week. Just continued cold here next week. No sign of warmth in the next 2 weeks.

[harpman]

The latest from Joe B: The Forces of Coldmeggedon already at Work in Europe are gathering for the US. Next week and beyond look wild!

[TexasBreeze]

It would most likely be a typical mid winter eastern us outbreak, nothing they've never seen before.