January: Calmer Pattern To End The Month

[hriverajr]

Storm2k seems to be down again.

[srainhoutx]

WPC Forecaster Paul Kocin presented a great update this morning regarding the volatility of the pattern that the Central and Eastern United States will be dealing with in the medium range....

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1058 AM EST TUE DEC 31 2013

VALID 12Z FRI JAN 03 2014 - 12Z TUE JAN 07 2014

A VERY WINTRY SCENARIO IN THE EAST STARTS OFF THE MEDIUM RANGE
FORECAST WITH A QUICK WARM UP IN THE CENTER OF THE COUNTRY. THE
WARM UP IS SHORT LIVED AS A NEW AND SIGNIFICANT OUTBREAK OF COLDER
AIR BEGINS TO ENTER THE NORTHERN ROCKIES AND PLAINS BY DAY
4/SATURDAY AND PROGRESSES EASTWARD BY SUNDAY DAY 5. WITH LARGE
UNCERTAIN IT STILL APPEARS THAT SOME FORM OF PRECIPITATION EVENT
WILL FORM IN ASSOCIATION WITH THIS NEXT OUTBREAK OF COLD AIR ON
DAY 5 INTO DAY 6/MONDAY...WITH A HUGE RANGE OF SOLUTIONS FROM A
FRONTAL PASSAGE TO A MAJOR CYCLONE. BY DAY 7/TUESDAY...MUCH OF
THE CENTRAL AND EASTERN US IS UNDER THE INFLUENCE OF BELOW TO MUCH
BELOW NORMAL TEMPERATURES.

A CUTOFF UPPER RIDGE OVER GREENLAND/NORTHEAST CANADA WILL HELP
RETAIN AN UPPER LOW OVER SOUTHEASTERN CANADA THAT CONTINUES TO
FORCE A TROUGH MOVING TOWARD THE EASTERN US TO REMAIN ON A PATH
CONDUCIVE TO SNOW OVER PORTIONS OF THE NORTHEAST US ON DAY 3.
WHILE THE DETAILS OF THE TROUGH EVOLUTION SEEM FAIRLY
STRAIGHTFORWARD DURING THE BEGINNING OF THE MEDIUM RANGE PERIOD
FOR THE ENSEMBLE MEANS AND THE EVOLUTION OF A COLD CANADIAN HIGH
BUILDING EASTWARD ACROSS SOUTHEASTERN CANADA ARE ALSO
STRAIGHTFORWARD...THE DETAILS OF THE ACTUAL TROUGH EVOLUTION AND
RESULTING SURFACE BAROCLINIC STRUCTURE REMAINS COMPLEX.
SIGNIFICANT MODEL SPREAD DUE TO THE LIKELIHOOD OF SEVERAL CENTERS
OF LOW PRESSURE OF VARYING STRENGTH COMING TOGETHER TO EVENTUALLY
FORM A CYCLONE OVER THE WESTERN ATLANTIC CONTINUES TO MAKE THIS A
CHALLENGING FORECAST EVEN AT THE START OF THE MEDIUM RANGE. IN
GENERAL...CONTINUITY FROM THE OVERNIGHT FORECAST IS MAINTAINED
BASED ON THE CONSISTENCY OF THE ECMWF ENSEMBLE MEANS WITH INPUT
FROM THE 00Z ECMWF AND 06Z GFS...BOTH OF WHICH MAINTAIN A SIMILAR
SPEED AND AMPLITUDE OF THE TROUGH NEARING THE EAST COAST. WITH THE
MAIN TROUGH NEARING THE EAST COAST BY FRIDAY MORNING...A MULTIPLE
CENTER SURFACE SYSTEM IS STILL EXPECTED WITH THE REMAINING
QUESTION BEING HOW INTENSE THE WESTERNMOST SURFACE LOW RESPONDS TO
THE UPPER LEVEL TROUGH WHILE OTHER SURFACE CENTER OR CENTERS SCOOT
FARTHER EASTWARD. IN ANY EVENT...WHATEVER SNOW IS FALLING ON
FRIDAY MORNING SHOULD BE MOVING EASTWARD OUT TO SEA DURING THE DAY
AS THE SYSTEM CONTINUES EASTWARD.

WITH A MEAN UPPER RIDGE TRENDING TO BUILD OVER THE EASTERN PACIFIC
FROM THE SHORT RANGE INTO THE MEDIUM RANGE...SEVERAL SHORTWAVE
SYSTEMS WILL BEGIN TO PROGRESS SOUTH AND EASTWARD OVER WESTERN
CANADA WHILE ANOTHER LARGE UPPER LOW OVER NW CANADA ALSO BEGINS TO
MOVE SOUTH AND EASTWARD AS WELL. BY DAY 5...ANOTHER LARGE VORTEX
WILL BE FOUND ACROSS SOUTH CENTRAL CANADA WITH A HUGE MASS OF
ARCTIC AIR POISED TO MOVE SOUTH AND EASTWARD ACROSS MUCH OF THE
CENTRAL AND EASTERN US. SIGNIFICANT DIFFERENCES ALSO CHARACTERIZE
THIS DEVELOPMENT WITH THE ECMWF ENSEMBLE MEANS SHOWING THE LARGEST
AMPLITUDE AND GREATER SOUTHWARD PUSH OF THE ARCTIC AIR WITH
GFS/NAEFS ENSEMBLE MEANS SHOWING A SLIGHTLY FLATTER
SCENARIO...ESPECIALLY BY DAY 6. WHILE THE 00Z ECMWF CREATES A
POTENTIALLY HISTORIC SCENARIO BY DAY 6...IT REMAINS A VERY LOW
PROBABILITY SOLUTION AS IT REMAINS MUCH MORE AMPLIFIED THAN THE
CORRESPONDING ECMWF ENSEMBLE MEAN SOLUTION. THE 06Z GFS ACTUALLY
LOOKS MORE LIKE THE 00Z ECMWF ENSEMBLE MEAN SOLUTION AND IS
SOMEWHAT FOLLOWED WHILE STILL SHOWING A VERY LARGE COLD OUTBREAK
MOVING INTO THE CENTRAL AND EASTERN US ON DAYS 6 INTO 7...WITH THE
DETAILS OF HOW LOW PRESSURE AT THE SURFACE ULTIMATELY DEVELOPING
ALONG THE LEADING EDGE OF THE COLD AIR STILL VERY MUCH UNCERTAIN
AT THIS POINT WITH A VERY MODEST SYSTEM SHOWN AT THE PRESENT TIME
BUT WILL LIKELY CHANGE SIGNIFICANTLY AS THE DAYS GET CLOSER.
CHANCES ARE THAT THIS NEXT SYSTEM WILL LIKELY ALSO BE A
SIGNIFICANT WINTER WEATHER EVENT SOMEWHERE FROM THE TENNESSEE AND
OHIO VALLEYS EASTWARD INTO THE NORTHEAST.

KOCIN

[cristina6871]

There are some significant changes via the 12Z Euro today. That model now suggests the much colder anomalies both in the temperatures expected and the placement of the mean trough axis is further W and S by hour 144.

I'm always trying to learn what the language on here means; can you tell me what this means?

[MontgomeryCoWx]

He's saying if the 12z Euro verified, we would be much colder and it wouldn't be a "glancing blow@

[srainhoutx]

The Climate Prediction Center just updated their Day 6-10 Outlook. Interesting to note the below normal temperatures and the above normal precipitation as well as some the analogs. The Analogs made a slight adjustment W today ~vs~ the outlook issued yesterday.

PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST TUE DECEMBER 31 2013

6-10 DAY OUTLOOK FOR JAN 06 - 10 2014

TODAY'S ENSEMBLE MEAN FORECASTS ARE IN FAIR AGREEMENT ON THE EXPECTED 500-HPA
HEIGHT PATTERN FOR THE 6-10 DAY PERIOD OVER NORTH AMERICA. ENSEMBLE MEANS FROM
THE ECMWF, GEFS, AND CANADIAN ENSEMBLES AGREE ON THE PREDICTION OF A 500-HPA
RIDGE EXTENDING FROM JUST OFF THE WEST COAST OF THE CONUS TO CENTRAL ALASKA.
MODELS AGREE ON BELOW-NORMAL HEIGHTS IN A BROAD TROUGH PREDICTED TO BE OVER THE
EAST-CENTRAL CONUS EXTENDING NORTHWARD TO HUDSON BAY. THE ECMWF ENSEMBLES AND
THE ECMWF DETERMINISTIC RUNS ARE IN GOOD AGREEMENT AND FAVOR A DEEPER TROUGH
THAN DO THE GEFS AND THE GFS DETERMINISTIC RUNS. THE CANADIAN ALSO FAVORS A
DEEPER TROUGH SO THE ECMWF ENSEMBLE MEAN IS WEIGHTED MOST HEAVILY IN TODAY'S
BLEND. THE ECMWF SOLUTIONS PREDICT A NOTABLY LESS SHARP RIDGE OVER ALASKA THAN
DO THE GEFS OR CANADIAN MODELS WHICH HAS SIGNIFICANT DOWNSTREAM CONSEQUENCES,
THUS CONFIDENCE IS LOWER THAN ON YESTERDAY'S OUTLOOK.

THERE IS VERY GOOD AGREEMENT FOR SIGNIFICANTLY BELOW NORMAL TEMPERATURES IN THE
NORTH-CENTRAL CONUS UNDER EXPECTED NORTHERLY UPPER LEVEL FLOW. HIGH
PROBABILITIES ARE ASSOCIATED WITH EXPECTED CONDITIONS EARLY IN THE 6-10 DAY
PERIOD. THE ECMWF'S DEEPER TROUGH WOULD PUSH COLD AIR INTO THE SOUTHEASTERN
CONUS, WHILE THE GEFS SUGGESTS LESS OF A SOUTHERN PUSH TO COLD AIR. THIS
UNCERTAINTY IS REFLECTED IN DIMINISHED PROBABILITIES THROUGHOUT THE EASTERN AND
SOUTHEASTERN CONUS FROM WHAT THE ECMWF SOLUTION WOULD IMPLY. TEMPERATURES IN
THE WESTERN CONUS ARE ALSO FAIRLY UNCERTAIN DUE TO CONFLICTING PREDICTIONS IN
THE STRENGTH OF THE TROUGH, AND SOME SUGGESTION BY THE CANADIAN ENSEMBLES FOR A
MEAN TROUGH AXIS FARTHER WEST THAN THE OTHER MODELS PREDICT. TELECONNECTIONS ON
THE POSITIVE ANOMALY CENTER IN 500-HPA HEIGHTS INDICATED BY THE MANUAL BLEND
ALSO SUGGEST THE CHANCE OF A TROUGH DEEPER AND FARTHER WEST THAN ITS LOCATION
ON THE MANUAL BLEND. THUS TEMPERATURE CONDITIONS ARE FAIRLY UNCERTAIN FOR MUCH
OF THE COUNTRY OUTSIDE OF THE NORTH-CENTRAL CONUS. THE OFFICIAL FORECAST
REFLECTS THE NEAR-SURFACE TEMPERATURES FROM THE ECMWF AND GEFS. TEMPERATURES IN
ALASKA ARE SIMILARLY UNCERTAIN IN VIEW OF THE ECMWF ENSEMBLE AND 12Z
DETERMINISTIC GFS PREDICTION OF A NEAR TO BELOW NORMAL 500-HPA HEIGHTS OVER THE
STATE, WHICH IS A SHARP CONTRAST TO OTHER MODELS AND YESTERDAY'S SOLUTIONS FOR
A FAIRLY STRONG RIDGE. ABOVE NORMAL TEMPERATURES IS STILL FAVORED, BUT WITH
LESS CERTAINTY THAN ON YESTERDAY'S OUTLOOK.

THE BROAD TROUGH EXPECTED OVER THE CENTRAL CONUS IS EXPECTED TO ELEVATE CHANCES
FOR NEAR TO ABOVE-MEDIAN PRECIPITATION AMOUNTS FOR MUCH OF THE EASTERN PART OF
THE COUNTRY. BELOW-MEDIAN PRECIPITATION IS FAVORED FOR MUCH OF THE SOUTHWESTERN
CONUS, WHICH IS EXPECTED TO BE TO THE WEST OF THE MEAN TROUGH AXIS. MODELS
INDICATE ABOVE-MEDIAN PRECIPITATION FOR THE NORTHERN ROCKIES, ALTHOUGH
CONFIDENCE IS NOT HIGH AND ELEVATED CHANCES ARE RESTRICTED TO A FAIRLY NARROW
BAND, REFLECTING SHORT WAVES MOVING SOUTHWARD IN THE MEAN NORTHWESTERLY FLOW
ALOFT. BELOW MEDIAN PRECIPITATION IS FAVORED FOR EASTERN ALASKA, WITH
ABOVE-MEDIAN PRECIPITATION FAVORED IN THE WEST, REFLECTING THE RIDGE AXIS
EXPECTED IN THE CENTRAL PART OF THE STATE DURING THE PERIOD.

TODAY'S OFFICIAL 500-HPA BLEND CONSISTS OF 10 PERCENT OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8...20 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8...40 PERCENT OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON
DAY 8...AND 30 PERCENT OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8.

MODEL OF THE DAY: TODAY'S 00Z ECMWF ENSEMBLE MEAN

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, WITH
ONLY FAIR AGREEMENT AMONG ENSEMBLE MEANS AND HINTS OF CONFLICTING PREDICTIONS
FOR CONDITIONS LATE IN THE 6-10 DAY PERIOD.

[Portastorm]

FWIW, the GFS for three consecutive runs now has shown the possibility of "wintry mischief" early next week in portions of Central and North Texas.

[ronyan]

The 12z GFS shows cold for next week but is too dry for precip. IAH below freezing on the 7th-8th for ~36hrs under apparently cloudy conditions, lows in the mid 20s with a sub 0 dewpoint!

[srainhoutx]

Well the Global ensembles and deterministic guidance did converge on an amplified pattern of that of a very strong Gulf of Alaska Ridge and a deep trough across the Plains and on East. There are still a lot of details to be worked out regarding what the sensible weather will actually be, but we now have agreement that a one/two shot of Arctic air will drop S across our Region and temperatures will turn sharply colder. I do notice a couple of short waves or upper air disturbances riding S from Western Canada and the Pacific NW into Arizona by Tuesday. One short wave/upper low looks rather potent and is depicted on all three of the Global models (Euro/GFS/Canadian). There are already hints of a Coastal trough/low attempting to develop early next week offshore of Brownsville, so we will have to monitor those finer details as they get a bit closer. It appears the 1050-1060mb Arctic high will deliver very cold air from Western Canada into much of the Eastern 2/3rds of the United States all the way to the Gulf Coast. The Arctic front is expected to drop as far S as the NW Caribbean Sea and Cuba, so it is a very strong cold front.

[srainhoutx]

Climate Prediction Center Day 6-10 Outlook issued:

PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST WED JANUARY 01 2014

6-10 DAY OUTLOOK FOR JAN 07 - 11 2014

TODAY'S ENSEMBLE MEAN FORECASTS ARE IN FAIR AGREEMENT ON THE EXPECTED 500-HPA
HEIGHT PATTERN FOR THE 6-10 DAY PERIOD OVER NORTH AMERICA. ENSEMBLE MEANS FROM
THE ECMWF, GEFS, AND CANADIAN ENSEMBLES AGREE ON THE PREDICTION OF BROAD
500-HPA TROUGH WITH AXIS EXTENDING FROM THE GREAT PLAINS TO HUDSON BAY. A RIDGE
IS PREDICTED OVER THE EASTERN NORTH PACIFIC, WITH DISAGREEMENT AMONG MODELS ON
ITS AMPLITUDE. THE ECMWF ENSEMBLE MEAN PREDICTS A MORE ZONAL FLOW OVER THE
NORTH PACIFIC THAN THE GEFS AND CANADIAN ENSEMBLE MEANS. THIS HAS IMPORTANT
IMPLICATIONS FOR THE LATER PART OF THE 6-10 DAY PERIOD SINCE A SHARPER RIDGE OR
DEEPER TROUGH WOULD INCREASE CHANCES OF ARCTIC AIR ENTERING THE CONUS. THE 00Z
ECMWF ENSEMBLE MEAN WAS WEIGHTED SLIGHTLY HIGHER THAN THE CANADIAN OR GEFS
ENSEMBLE MEANS IN TODAY'S BLEND REFLECTING AGREEMENT WITH THE 00Z GFS
DETERMINISTIC RUN.

THE CHANCES FOR BELOW-NORMAL TEMPERATURES ARE SUBSTANTIALLY ELEVATED IN THE
EASTERN HALF OF THE CONUS. THIS IS PRIMARILY DUE TO COLD CONDITIONS FORECAST
EARLY IN THE PERIOD. TEMPERATURES IN THE CENTRAL AND WESTERN CONUS WILL DEPEND
ON THE AMPLITUDE OF THE CIRCULATION OVER THE EASTERN NORTH PACIFIC AND WESTERN
NORTH AMERICA. THE MORE ZONAL SOLUTION OF THE ECMWF ENSEMBLES WOULD PRODUCE
RELATIVELY MILD CONDITIONS IN THE WESTERN PART OF THE COUNTRY, WHILE THE
SHARPER TROUGHS OF THE CANADIAN MODEL ENSEMBLES WOULD INCREASE CHANCES OF COLD
CONDITIONS IN THE CENTRAL AND WEST-CENTRAL CONUS. THE TEMPERATURE OUTLOOK
FOLLOWS THE LOW-LEVEL TEMPERATURES PREDICTED BY THE GEFS ENSEMBLES WITH
TEMPERATURES REDUCED SOMEWHAT IN THE NORTHERN ROCKIES AND PACIFIC NORTHWEST TO
REFLECT THE POSSIBILITY SUGGESTED BY THE CANADIAN ENSEMBLES. TEMPERATURES IN
ALASKA ARE UNCERTAIN IN VIEW OF THE ECMWF ENSEMBLE AND 12Z DETERMINISTIC GFS
PREDICTION OF A NEAR TO BELOW-NORMAL 500-HPA HEIGHTS OVER THE STATE, WHICH IS
IN CONTRAST TO THE CANADIAN AND MANY GEFS ENSEMBLE SOLUTIONS THAT MAINTAIN A
RIDGE OVER THE STATE. ABOVE-NORMAL TEMPERATURES ARE ONLY SLIGHTLY FAVORED IN
MOST OF ALASKA.

THE BROAD TROUGH PREDICTED OVER THE CENTRAL CONUS IS EXPECTED TO ELEVATE
CHANCES FOR NEAR- TO ABOVE-MEDIAN PRECIPITATION AMOUNTS FOR MUCH OF THE EASTERN
PART OF THE COUNTRY. CHANGES BETWEEN YESTERDAY'S AND TODAY'S PRECIPITATION
OUTLOOK IN THE NORTHEAST REFLECT THE TIMING OF AN EXPECTED PRECIPITATION EVENT
EARLY IN THE PERIOD, WHICH EXITS THE REGION BEFORE THE START OF TODAY'S 6-10
DAY PERIOD. THE GEFS REFORECAST TOOL NOW FAVORS BELOW-MEDIAN PRECIPITATION
TOTALS FOR PARTS OF THE NORTHEAST. ELEVATED CHANCES FOR ABOVE-MEDIAN
PRECIPITATION IN THE SOUTHEAST AND WESTERN GULF STATES REFLECTS EXPECTED RETURN
FLOW LATE IN THE PERIOD AROUND THE INITIALLY COLD HIGH PRESSURE SYSTEM. THE
GEFS ENSEMBLES CONTINUE TO INDICATE ABOVE-MEDIAN PRECIPITATION FOR THE NORTHERN
ROCKIES. BELOW-MEDIAN PRECIPITATION IS FAVORED FOR NORTHERN ALASKA, WITH
ABOVE-MEDIAN PRECIPITATION FAVORED IN THE SOUTHERN PART OF THE STATE REFLECTING
THE CHANCES FOR AN ENHANCED JET OVER THE GULF OF ALASKA PREDICTED BY THE ECMWF
AND SOME GEFS ENSEMBLE SOLUTIONS. BELOW-MEDIAN PRECIPITATION AMOUNTS CONTINUE
TO BE FAVORED IN THE SOUTHWESTERN CONUS BEHIND THE EXPECTED TROUGH AXIS.

TODAY'S OFFICIAL 500-HPA BLEND CONSISTS OF 10 PERCENT OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8...20 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8...40 PERCENT OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON
DAY 8...AND 30 PERCENT OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8.

MODEL OF THE DAY: TODAY'S 00Z ECMWF ENSEMBLE MEAN

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, WITH
ONLY FAIR AGREEMENT AMONG ENSEMBLE MEANS AND HINTS OF CONFLICTING PREDICTIONS
FOR CONDITIONS LATE IN THE 6-10 DAY PERIOD.

[srainhoutx]

A strong cold front is pushing S across N Texas at this hour. Light snow is falling just NE of Amarillo and across Northern Oklahoma ushering in much colder air. Tomorrow we will be lucky to reach 50F with gusty NW winds. The high for tomorrow will likely be whatever the lows tonight are reached before the front passes.

[TxJohn]

A strong cold front is pushing S across N Texas at this hour. Light snow is falling just NE of Amarillo and across Northern Oklahoma ushering in much colder air. Tomorrow we will be lucky to reach 50F with gusty NW winds. The high for tomorrow will likely be whatever the lows tonight are reached before the front passes.

Srain, are we still expecting the "big" arctic blast around the 11th/12th?

Also I noticed that next week we remain cloudy even with our 20 degree weather...and rain around that time period. A local met said the upper air pattern doesn't favor snow so there's no chance....what do they mean by this? I remember you said watch out for the middle of next week...

[srainhoutx]

A much stronger Arctic front arrives Saturday night/early Sunday, John. It appears a re enforcing shot of much colder air arrives Monday into Tuesday of next week. I don't see a big moderation regarding the colder temps next week due to a strong NE wind blowing down from where the coldest air will be located. Parts of the Ohio and Mid Mississippi Valley Region may see temps near or below zero with wind chill indices near -10 to -20F.

[unome]

colder & definitely windy this morning, but it's winter after all...

this, however, is kicking my butt

http://pollen.utulsa.edu/cedar.html

http://www.pollen.com/allergy-weather-forecast.asp



the juniper/cedar pollen can even be "low" & it bothers me, time to stock up on allergy meds again !

[wxman57]

Srain, are we still expecting the "big" arctic blast around the 11th/12th?

Also I noticed that next week we remain cloudy even with our 20 degree weather...and rain around that time period. A local met said the upper air pattern doesn't favor snow so there's no chance....what do they mean by this? I remember you said watch out for the middle of next week...

No big Arctic blast is evident in the long-range models. Euro ensembles have Houston in the 50s-60s around the 11th. Next week's cold will be quite short-lived, and with northwest flow aloft (and no passing disturbances) it will be a quite dry cold.

[Portastorm]

colder & definitely windy this morning, but it's winter after all...

this, however, is kicking my butt

http://pollen.utulsa.edu/cedar.html

http://www.pollen.com/allergy-weather-forecast.asp



the juniper/cedar pollen can even be "low" & it bothers me, time to stock up on allergy meds again !

Unfortunately, I'm in the same boat although my daily antihistamine seems to be losing the battle at the moment. No wonder. I just saw a tweet from Austin TV met Mark Murray (KVUE) who said today's cedar pollen count is the highest they've registered in 15 years of recording cedar pollen count values.

[srainhoutx]

Morning Update from Jeff:

Strong cold front has progressed across the area this morning leaving cold and gusty north winds in its wake.

Temperatures have continued to fall this morning under strong cold air advection regime in progress with current readings in the low to mid 30’s up north and near 40 along the coast with N winds of 15-25mph and gusts to 40mph. In the past hour Galveston has gusted to 40mph. Low temperatures combined with the strong winds have driven wind chill values into the low 20’s over our northern counties. A wind advisory is in effect for the central and southern parts of the area today, but think this will be marginal with only a few gust to near 40mph mainly before noon. High level cirrus clouds continue to spill NNE across the area, but should gradually push southward leaving mainly clear skies by late afternoon. Not sure temperatures will warm much…and think the mid to upper 40’s this afternoon will be all we can manage under continued cold air advection and partly to mostly cloudy skies.

Quick hitting polar high will be situated over N TX tonight leading to a very cold night across the region. Dewpoints falling into the 10’s and 20’s by late this afternoon with clear skies and expected light winds will result in a widespread freeze across the area tonight. Lows will likely range from the mid 20’s up north to upper 20’s along US 59 to near freezing along the coast. Could see a few locations very near hard freeze criteria tonight especially in those usually cold locations (Conroe).

Polar high moves quickly eastward Friday with southerly wind returning. Clouds expand northward on Saturday and possibly enough moisture return for a few showers with temperatures warming back into the 60’s in a similar day to New Year’s Day.

Big question is how strong will be next front be on Sunday. Pretty good pool of very cold air currently over NW Canada and this appears poised to head SE into the US this weekend. Appears TX will be on the SW edge of this bitter cold air mass, but close enough to possibly produce some of the coldest weather since early 2011. Arctic boundary should pass across the region Sunday morning with temperatures quickly falling during the day on Sunday. GFS model is forecasting some “really” low dewpoints into the 10’s and 1’s across the region by next Monday and with mainly clear skies and a 1038mb arctic high centered over OK by Monday evening it could get fairly cold by Tuesday morning. Current GFS model guidance shows IAH falling to 25 Tuesday morning suggesting hard freeze criteria will be possible for a large part of the region NW of US 59 with lows possibly in the 10’s over our northern counties (GFS currently showing a 21 for College Station). Will have to keep a close eye on just how much of this cold air moves southward and potentially how cold it could get across the area early next week.

Climate:

2013 ended just as the previous four years with below average rainfall across much of the area. BUSH IAH ended the year with 38.84 inches of rainfall or 10.93 inches below normal. Hobby Airport ended 11.59 inches below normal and Galveston 11.52 inches below normal. College Station faired the best with a rainfall departure of only .71 of an inch below normal. I took a look back at the climate for the past 10 years at BUSH IAH and some impressive rainfall statistics emerged.

The normal annual rainfall for BUSH IAH is 49.77 inches:

Recorded rainfall by year:

2003: 45.76

2004: 65.06

2005: 41.21

2006: 57.86

2007: 65.52

2008: 53.00



2009: 47.01

2010: 42.72

2011: 24.57

2013: 42.32

2013: 38.84

The 5-yr total from 2003 to 2008 was 328.85 inches or 79.56 inches above normal for that 5-yr period

The 5-yr total from 2009 to 2013 was 195.46 inches or 53.39 inches below normal

Note that 2013 is the second driest year in the past 10 years only behind the severe drought year of 2011.

To put this into some perspective there is a 132.95 inch rainfall difference between the first 5-yr block and the second 5-yr block. The last 5 years have been very dry across the region and this dry pattern started after the landfall of Hurricane Ike in September 2008. However if you average out the rainfall over the past 10 years BUSH IAH is running a 26.17 inch rainfall surplus and this is due to the “very wet” years from 2003 to 2008 especially 2004 and 2007. A longer term trend in the climate signal would show a rainfall surplus for the area even though the last five years have been dry. It is also interesting to note that the rainfall deficit from 2009 to 2013 of 53.59 inches is over an entire year’s worth of rainfall missing (49.77 inches) where the period from 2003 to 2008 has a surplus of 79.56 inches or well over a year’s worth of rainfall on the positive side…so both astounding statistics effectively cancel each other out in the 10 year averaging of the rainfall.

On the temperature side of things 2013 ended slightly below normal (-.3 of a degree) and this coming off of the hottest year ever recorded for Houston in 2012 and previous very warm years in 2011 and 2010. Much of this cooling was in December which averaged almost 2-4 degrees below normal across the region…so yes it has been cold so far this winter.

[jasons2k]

My wife suffered from allergies for the very first time in her life, this past weekend, while in Austin.

Those rainfall statistics are amazing. Would like to see further analysis on what's different between the two periods.

[srainhoutx]

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1110 AM EST THU JAN 02 2014

VALID 12Z SUN JAN 05 2014 - 12Z THU JAN 09 2014

...SOME OF THE COLDEST AIR IN RECENT HISTORY WILL SPREAD INTO THE
MIDWEST...GREAT LAKES...OHIO VALLEY...NORTHEAST...AND MID-ATLANTIC
STATES EARLY NEXT WEEK...


...GENERAL FLOW PATTERN AND MODEL PREFERENCES...

THE DOMINANT FEATURE EARLY IN THE PERIOD WILL BE A DEEP VORTEX
SPINNING ALONG THE NORTH CENTRAL U.S./SOUTHERN CANADIAN
BORDER....WHICH WILL CARVE OUT ANOMALOUS HEIGHT FALLS OVER THE
EASTERN HALF OF THE NATION. A LEADING SHORTWAVE WITHIN THE BROAD
TROUGH WILL INTENSIFY A SURFACE LOW WHILE IT TRACKS FROM THE LOWER
MISSISSIPPI VALLEY TO INTERIOR NEW ENGLAND SUNDAY INTO
MONDAY...AND AS THE DEEP VORTEX LIFTS OUT INTO EASTERN
CANADA...STRONG SURFACE HIGH PRESSURE WILL FILL IN BEHIND IT.
ALSO...AN UPSTREAM RIDGE BEGINNING TO SUPPRESS OVER THE WESTERN
U.S. SHOULD ALLOW A SERIES OF WEAK IMPULSES ALOFT TO MOVE INLAND
OVER THE WEST BY THE MIDDLE OF NEXT WEEK.

MODELS HAVE COME INTO VERY GOOD AGREEMENT WITH THE EVOLUTION OF
THE ANOMALOUS TROUGH DIGGING INTO THE CENTRAL/EASTERN U.S. AND
WITH THE TIMING OF THE ASSOCIATED STRONG ARCTIC FRONT PUSHING
EASTWARD ACROSS THE APPALACHIANS ON SUNDAY. ADDITIONALLY...THE
06Z GFS/00Z ECMWF APPEAR TO BE ON THE SAME PAGE WITH THE
TRACK/DEPTH OF THE DEEPENING SURFACE LOW LIFTING OUT OF THE LOWER
MISSISSIPPI VALLEY AT THE START OF THE FORECAST PERIOD. OUT
WEST...ALTHOUGH GUIDANCE IS ALL IN FAVOR OF SUPPRESSING THE RIDGE
OVER THE WESTERN CONUS AND ALLOWING WEAK SHORTWAVE ENERGY TO MOVE
ONSHORE...THERE ARE STILL IMPORTANT DETAIL DIFFERENCES THAT NEED
TO BE RESOLVED. CURRENTLY...THE 00Z ECMWF ENSEMBLE MEAN APPEARS
TO OFFER THE MOST REASONABLE SOLUTION SINCE IT HINTS AT MORE OF A
SPLIT FLOW REGIME IN THE EASTERN PACIFIC IN RESPONSE TO THE
DOWNSTREAM RIDGE IN PLACE OVER BRITISH COLUMBIA.

THE WPC DAY 3-7 FORECAST WAS BASED PREDOMINANTLY ON THE 00Z ECMWF
ENSEMBLE MEAN...WHICH ALIGNED WELL WITH THE AGREEMENT BETWEEN THE
06Z GFS/00Z ECMWF FOR THE SURFACE LOW LIFTING OUT OF THE LOWER
MISSISSIPPI VALLEY AND SEEMS TO HAVE A BETTER HANDLE ON IMPULSES
MOVING INTO THE WESTERN U.S. FOR THE SECOND HALF OF THE FORECAST
PERIOD.


...SENSIBLE WEATHER HIGHLIGHTS...

A FRIGID AIRMASS SPREADING OVER THE MIDWEST...GREAT LAKES...OHIO
VALLEY...NORTHEAST...AND MID-ATLANTIC STATES WILL BE THE BIG STORY
EARLY NEXT WEEK. WIDESPREAD TEMPERATURE ANOMALIES OF -10 TO -20
DEGREES ARE EXPECTED ACROSS MUCH OF THE CENTRAL AND EASTERN
U.S....BUT THE EPICENTER OF THE BITTER COLD SHOULD BE ACROSS THE
OHIO VALLEY...WHICH COULD SEE TEMPERATURES NEARLY 40 DEGREES BELOW
NORMAL BY MONDAY. IN ADDITION TO THE COLD...A SWATH OF HEAVY SNOW
SHOULD SET UP TO THE NORTHWEST OF THE SURFACE LOW TRACKING FROM
THE LOWER MISSISSIPPI VALLEY TO INTERIOR NEW ENGLAND. THE SURFACE
CYCLONE WILL ALSO BRING STRONG AND GUSTY WINDS ACROSS THE GREAT
LAKES REGION AS IT RAPIDLY DEEPENS WHILE WRAPPING INLAND OVER
EASTERN CANADA MONDAY NIGHT INTO TUESDAY. TEMPERATURE SHOULD
BEGIN TO MODERATE ACROSS THE EASTERN HALF OF THE NATION BY THE
MIDDLE OF NEXT WEEK.

INITIALLY DRY CONDITIONS OUT WEST WILL GIVE WAY TO INCREASING
AMOUNTS OF MOISTURE. WEAK ENERGY MOVING IN ALOFT SHOULD BRING
ROUNDS OF PRECIPITATION INTO THE PACIFIC NORTHWEST/INTERMOUNTAIN
WEST/GREAT BASIN BY THE MIDDLE OF THE NEXT WEEK.


GERHARDT

[cristina6871]

srainhoutx - can you tell me what your last post means for SE Texas? from what I've been reading, it's not going to get really cold in the long term for us.

[redneckweather]

Hello Cristina. The core of the arctic air will slide off to the northeast but we will get a good glancing blow. Cold but dry air will be in store for us the beginning of next week. Nothing out of the ordinary for this time of year. Don't get me wrong, it will be a strong front (short lived) but nothing we haven't seen before.