Winter Weather

[jeffl]

Significant coastal Nor'easter from the mid-ATL to New England Sunday through Tuesday.

First true arctic blast of the season arrives late Saturday at the US border and sweeps across the SE on Monday. TX will get a glancing blow, but the SE and FL will feel the full brunt of the cold air. Lows in the mid 20's as far south as central Fl will be possible. This appears to be just a small taste.

Major pattern amplification takes place after Monday with a hugh downstream trough over the central and eastern US. Very cold (-60F) Siberian air begins to move across the N pole and then southward into Canada by the 23 and 24th. Full blown McFarland pattern is established by the 25th with cross polar flow and strong blocking over Greenland. The arctic flood gates will be opened on the US with bitter cold air pouring south down the front range and deep into the Gulf. Details are still tricky, but the upper pattern supports very cold air entering the US and then overtaking the eastern 2/3rds of the nation by the day after Christmas. We may have to go all the way back to 1989 to find a similar pattern setup and cold air outbreak.

[BaytownWeatherWatcher]

What kind of temps can we expect in the Houston area when the really cold air arrives here and is there still the chance of snow?

[ticka1]

Even the NWS is seeing this too - check out today's forecast.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
325 AM CST THU DEC 16 2004

.DISCUSSION...
RAIN WHICH IS DEVELOPING ACROSS SE TX WILL BECOME MORE WIDESPREAD
OVER THE NEXT FEW HOURS AS AIRMASS BECOMES SATURATED. MODELS
INDICATE THAT WARM ADVECTION AND LIFT WILL BE MAXIMIZED FROM 12Z TO
21Z SO THIS IS WHEN THE MOST SIGNIFICANT RAIN SHOULD OCCUR.
EXPECTING LIGHT PRECIP AMOUNTS (1/4 TO 1/2 INCH) WITH ISOLATED
TOTALS TO NEAR AN INCH POSSIBLE NEAR THE COAST. HAVE GONE
CATEGORICAL POPS FOR THE SOUTHEAST...AND LIKELY OVER THE NORTH/WEST
ZONES TODAY. WILL KEEP MENTION OF THUNDER CONFINED TO THE COASTAL
WATERS. TEMPS WILL WARM VERY LITTLE TODAY WITH ALL THE CLOUDS/RAIN.

ETA/GFS DIFFER ON WHEN ALL THE CLOUDS AND MOISTURE MOVE OUT OF SE
TX. FOLLOWED THE ETA SOLUTION SINCE IT HAS HAD A BETTER HANDLE ON
THIS SYSTEM ALL ALONG. 500 MB TROF AXIS REMAINS WEST OF THE AREA
TONIGHT SO KEPT CHANCE POPS GOING THIS EVENING WITH LIKELY OVER THE
SOUTHEAST. LOW CLOUDS SHOULD REMAIN IN PLACE TONIGHT SO KEPT TEMPS
ABOVE GUIDANCE. ON FRIDAY...HAVE LINGERING POPS CENTRAL/SOUTH IN THE
MORNING THEN WILL SHOW DECREASING CLOUDS IN THE AFTERNOON. THE ETA
BRINGS ANOTHER SHORTWAVE TOWARD THE AREA SATURDAY. ETA MOS GUIDANCE
NOW HAS POPS FOR SATURDAY BUT KEPT PRECIP OUT OF THE FORECAST AS
EXPECT PWS WILL BE LESS THAN A HALF INCH AT THIS POINT.

00Z MODEL RUNS HAVE CONTINUED THEIR TREND OF SHOWING A STRONG COLD
FRONT CROSSING THE AREA SATURDAY NIGHT OR EARLY SUNDAY. THE AIRMASS
BEHIND THIS FRONT WILL ORIGINATE IN NORTHERN CANADA. IN FACT...GFS
SHOWS 850 MB TEMPS DROPPING TO -3 TO -6 OVER THE AREA 00Z MONDAY.
HAVE LOWERED TEMPS CLOSER TO MEX NUMBERS FOR SUN-MON ACCORDINGLY.
WILL LIKELY SEE ANOTHER WIDESPREAD FREEZE SUNDAY NIGHT.

THE FORECAST FOR NEXT WEEK LOOKS VERY INTERESTING. THE COLD AIRMASS
WILL MOVE QUICKLY EAST EARLY IN THE WEEK WITH RETURN FLOW BECOMING
ESTABLISHED. SHOULD SEE WARMER TEMPS TUESDAY THROUGH THURSDAY AS LOW
LEVEL SOUTHWEST FLOW DEVELOPS. NOT TOO EXCITED ABOUT RAIN THESE
PERIODS WITH 850 MB WINDS OUT OF THE SOUTHWEST. IN THE MEANTIME
ARCTIC AIR WILL BE PILING UP ACROSS THE NORTHERN PLAINS/ROCKIES AS A
DEEP LONGWAVE TROF DEVELOPS IN THIS AREA. SOME OF THIS COLD AIR
COULD EVENTUALLY DROP SOUTH ACROSS TEXAS...POSSIBLY DURING THE
HOLIDAY WEEKEND. TOO SOON TO TELL BUT SOMETHING THAT BEARS WATCH.