Deep South Winterwx Discussion 2015-2016

[Sabanic]

That's true but we gotta hope . . . Local news here just showed a 70% chance of precipitation Thursday and Thursday evening. Up considerably from the 30-40% this morning. That combined with a forecasted low of around 21 may not be snow, but it surely will not be rain.

[Dean4Storms]

hmm so what does the blue line indicate on this image of the NAM?

that means that at 1000mb will be colder than at higher altitudes.

1000-850 thickness looks like snow:


but 850-700 thickness is too warm:


so freezing rain sounds more likely

More likely sleet, then I think a change over to some snow before ending. Of course this is still 3 days out so just a little change and this could go either way.

[Brent]

This is strange to be out so early...

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE NEW ORLEANS LA
633 PM CST MON JAN 4 2010

...WINTRY MIX FOLLOWED BY AN ARCTIC OUTBREAK IS ON THE WAY...

.THE FIRST IN A WAVE OF ARCTIC AIRMASSES IS ALREADY MOVING IN
TONIGHT BUT FOR THE SECOND HALF OF THE WEEK WE WILL SEE A GULF LOW
DEVELOP AND MOVE ACROSS THE NORTHERN GULF WITH A MUCH STRONGER
ARCTIC AIRMASS QUICKLY ON THE HEELS OF THIS SYSTEM. WITH THE MUCH
COLDER AIR MOVING INTO THE GULF COAST STATES THERE IS THE RISK OF
RAIN QUICKLY CHANGING OVER TO SLEET AND SNOW EARLY THURSDAY
MORNING ACROSS PORTIONS OF THE OUTLOOK AREA. ADDITIONALLY...VERY
COLD TEMPERATURES WILL MOVE INTO THE REGION FOR THURSDAY NIGHT
THROUGH SUNDAY.

LAZ034>040-046>050-056>070-MSZ068>071-077-080>082-050845-
/O.NEW.KLIX.WW.Y.0001.100107T0000Z-100110T1600Z/
POINTE COUPEE-WEST FELICIANA-EAST FELICIANA-ST. HELENA-TANGIPAHOA-
WASHINGTON-ST. TAMMANY-IBERVILLE-WEST BATON ROUGE-
EAST BATON ROUGE-ASCENSION-LIVINGSTON-ASSUMPTION-ST. JAMES-
ST. JOHN THE BAPTIST-UPPER LAFOURCHE-ST. CHARLES-UPPER JEFFERSON-
ORLEANS-UPPER PLAQUEMINES-UPPER ST. BERNARD-UPPER TERREBONNE-
LOWER TERREBONNE-LOWER LAFOURCHE-LOWER JEFFERSON-
LOWER PLAQUEMINES-LOWER ST. BERNARD-WILKINSON-AMITE-PIKE-WALTHALL-
PEARL RIVER-HANCOCK-HARRISON-JACKSON-
INCLUDING THE CITIES OF...NEW ROADS...LIVONIA...
ST. FRANCISVILLE...JACKSON...CLINTON...GREENSBURG...MONTPELIER...
HAMMOND...PONCHATOULA...BOGALUSA...FRANKLINTON...SLIDELL...
MANDEVILLE...COVINGTON...LACOMBE...PLAQUEMINE...WHITE CASTLE...
PORT ALLEN...ADDIS...BRUSLY...BATON ROUGE...GONZALES...
DONALDSONVILLE...DENHAM SPRINGS...WALKER...PIERRE PART...
LABADIEVILLE...PAINCOURTVILLE...LUTCHER...GRAMERCY...LAPLACE...
RESERVE...THIBODAUX...RACELAND...LAROSE...DESTREHAN...NORCO...
METAIRIE...KENNER...NEW ORLEANS...BELLE CHASSE...CHALMETTE...
VIOLET...HOUMA...BAYOU CANE...CHAUVIN...DULAC...MONTEGUT...
GALLIANO...CUT OFF...GOLDEN MEADOW...PORT SULPHUR...EMPIRE...
YSCLOSKEY...CENTREVILLE...WOODVILLE...GLOSTER...LIBERTY...
CROSBY...MCCOMB...TYLERTOWN...PICAYUNE...BAY ST. LOUIS...
WAVELAND...DIAMONDHEAD...GULFPORT...BILOXI...PASCAGOULA...
OCEAN SPRINGS...MOSS POINT...GAUTIER...ST. MARTIN
633 PM CST MON JAN 4 2010

...WINTER WEATHER ADVISORY IN EFFECT FROM 6 PM WEDNESDAY TO 10 AM
CST SUNDAY...

THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A WINTER
WEATHER ADVISORY FOR AN EXPECTED WINTER MIX AND EXTREMELY COLD
TEMPERATURES...WHICH IS IN EFFECT FROM 6 PM WEDNESDAY TO 10 AM CST
SUNDAY.

BY LATE WEDNESDAY NIGHT OR EARLY THURSDAY MORNING...A SURFACE LOW
WILL START TO DEVELOP OVER THE NORTHWESTERN GULF. THIS WILL CAUSE
TEMPERATURES TO WARM SLOWLY WITH MOISTURE INCREASING ACROSS THE AREA.
INITIALLY...LIGHT TO MODERATE SHOWERS WILL BE POSSIBLE BUT BY
LATE THURSDAY MORNING...A VERY COLD AIRMASS WILL BEGIN TO PUSH
INTO THE REGION. RAIN WILL BEGIN TO CHANGE OVER TO SLEET AND THEN
SNOW THURSDAY MORNING FOR AREAS IN SOUTHERN MISSISSIPPI ALONG
WITH THE FELICIANAS AND POINT COUPEE PARISH. BY THURSDAY AFTERNOON
AREAS ALONG AND NORTH OF THE 10/12 CORRIDOR WILL LIKELY SEE A MIX
OF RAIN...SLEET...AND SNOW. AT THIS TIME WE ARE NOT EXPECTING MUCH
IN THE WAY OF ACCUMULATION BUT A LIGHT DUSTING TO HALF AN INCH OF
ACCUMULATION ON GRASSY AREAS WOULD NOT BE OUT OF THE QUESTION.

ALL OF THE MOISTURE WILL MOVE OUT OF THE AREA BY THURSDAY EVENING
AND THEN THE GREATER ISSUE ARRIVES...VERY COLD TEMPERATURES. AN
ARCTIC AIRMASS WILL CONTINUE TO MOVE IN AND REMAIN OVER THE AREA
FROM THURSDAY NIGHT THROUGH SUNDAY. THIS AIRMASS IS ASSOCIATED
WITH NEAR -40 DEGREE TEMPERATURES IN THE INTERIOR OF CANADA. WITH
A NICE SNOW PACK ACROSS THE UPPER AND CENTRAL PLAINS AS WELL AS THE
UPPER AND MID MISSISSIPPI VALLEY THE AIRMASS WILL NOT MODERATE
CONSIDERABLY. THE AIRMASS IS EXPECTED TO BRING VERY COLD
TEMPERATURES TO THE AREA THAT COULD BE COMPARABLE TO THE ARCTIC
OUTBREAK OF EARLY FEBRUARY 1996...BUT NOT AS LOW AS THOSE
EXPERIENCED DURING THE 1985 AND 1989 ARCTIC OUTBREAKS. MULTIPLE
NIGHTS WITH LOWS IN THE TEENS WILL BE POSSIBLE ACROSS SOUTHERN
MISSISSIPPI AND PORTIONS OF SOUTHEAST LOUISIANA THAT ARE GENERALLY
NORTH OF THE 10/12 CORRIDOR. ACROSS THE SOUTHSHORE...LOWS COULD
DROP TO INTO THE LOWER TO MID 20S FOR MULTIPLE NIGHTS. THE COLDEST
TEMPERATURES ARE CURRENTLY FORECAST TO OCCUR SATURDAY MORNING WITH
LOWS RANGING FROM 13 NEAR MCCOMB TO 23 AT GALLIANO. EVEN THOUGH IT
IS NOT FORECAST RIGHT NOW...THIS AIRMASS DOES HAVE THE POTENTIAL
TO CAUSE LOWS THAT COULD BOTTOM OUT IN THE SINGLE DIGITS ACROSS
ISOLATED LOCATIONS IN SOUTHERN MISSISSIPPI AND MAYBE INTO THE
TEENS AROUND THE NEW ORLEANS METRO.

THESE TEMPERATURES COULD BECOME LIFE THREATENING AND AT THE VERY
LEAST HAZARDOUS TO PROPERTY. RESIDENTS SHOULD MAKE PREPARATIONS
FOR EXTREMELY COLD TEMPERATURES NOW.

TO PREVENT FREEZING AND POSSIBLE BURSTING OF OUTDOOR PIPES...
PIPES SHOULD BE WRAPPED...DRAINED...OR ALLOWED TO DRIP SLOWLY.
THOSE THAT HAVE IN-GROUND SPRINKLER SYSTEMS SHOULD DRAIN THEIR
SYSTEMS...OR COVER ANY ABOVE-GROUND PIPES TO PROTECT THEM FROM
FREEZING.

PETS ARE ALSO SUBJECT TO THE EXTREME COLD. KEEP PETS INDOORS AS
MUCH AS POSSIBLE. IF THIS IS NOT POSSIBLE...MAKE SURE OUTDOOR
PETS HAVE WARM DRY SHELTER...AND PROVIDE SUFFICIENT FOOD AND
FRESH UNFROZEN WATER.

BE PARTICULARLY CAREFUL WITH PORTABLE HEATERS...THERE IS A DANGER
OF FIRE OR POISONOUS FUMES. MAKE FREQUENT CHECKS ON THE ELDERLY.
MAKE SURE THEIR FURNACES ARE WORKING AND HEATING THE HOUSE
PROPERLY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY MEANS THAT PERIODS OF SNOW...SLEET...OR
FREEZING RAIN WILL CAUSE TRAVEL DIFFICULTIES. BE PREPARED FOR
SLIPPERY ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING.

&&

$$

CAB

[Big Easy]

This is strange to be out so early...

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE NEW ORLEANS LA
633 PM CST MON JAN 4 2010

...WINTRY MIX FOLLOWED BY AN ARCTIC OUTBREAK IS ON THE WAY...

.THE FIRST IN A WAVE OF ARCTIC AIRMASSES IS ALREADY MOVING IN
TONIGHT BUT FOR THE SECOND HALF OF THE WEEK WE WILL SEE A GULF LOW
DEVELOP AND MOVE ACROSS THE NORTHERN GULF WITH A MUCH STRONGER
ARCTIC AIRMASS QUICKLY ON THE HEELS OF THIS SYSTEM. WITH THE MUCH
COLDER AIR MOVING INTO THE GULF COAST STATES THERE IS THE RISK OF
RAIN QUICKLY CHANGING OVER TO SLEET AND SNOW EARLY THURSDAY
MORNING ACROSS PORTIONS OF THE OUTLOOK AREA. ADDITIONALLY...VERY
COLD TEMPERATURES WILL MOVE INTO THE REGION FOR THURSDAY NIGHT
THROUGH SUNDAY.

LAZ034>040-046>050-056>070-MSZ068>071-077-080>082-050845-
/O.NEW.KLIX.WW.Y.0001.100107T0000Z-100110T1600Z/
POINTE COUPEE-WEST FELICIANA-EAST FELICIANA-ST. HELENA-TANGIPAHOA-
WASHINGTON-ST. TAMMANY-IBERVILLE-WEST BATON ROUGE-
EAST BATON ROUGE-ASCENSION-LIVINGSTON-ASSUMPTION-ST. JAMES-
ST. JOHN THE BAPTIST-UPPER LAFOURCHE-ST. CHARLES-UPPER JEFFERSON-
ORLEANS-UPPER PLAQUEMINES-UPPER ST. BERNARD-UPPER TERREBONNE-
LOWER TERREBONNE-LOWER LAFOURCHE-LOWER JEFFERSON-
LOWER PLAQUEMINES-LOWER ST. BERNARD-WILKINSON-AMITE-PIKE-WALTHALL-
PEARL RIVER-HANCOCK-HARRISON-JACKSON-
INCLUDING THE CITIES OF...NEW ROADS...LIVONIA...
ST. FRANCISVILLE...JACKSON...CLINTON...GREENSBURG...MONTPELIER...
HAMMOND...PONCHATOULA...BOGALUSA...FRANKLINTON...SLIDELL...
MANDEVILLE...COVINGTON...LACOMBE...PLAQUEMINE...WHITE CASTLE...
PORT ALLEN...ADDIS...BRUSLY...BATON ROUGE...GONZALES...
DONALDSONVILLE...DENHAM SPRINGS...WALKER...PIERRE PART...
LABADIEVILLE...PAINCOURTVILLE...LUTCHER...GRAMERCY...LAPLACE...
RESERVE...THIBODAUX...RACELAND...LAROSE...DESTREHAN...NORCO...
METAIRIE...KENNER...NEW ORLEANS...BELLE CHASSE...CHALMETTE...
VIOLET...HOUMA...BAYOU CANE...CHAUVIN...DULAC...MONTEGUT...
GALLIANO...CUT OFF...GOLDEN MEADOW...PORT SULPHUR...EMPIRE...
YSCLOSKEY...CENTREVILLE...WOODVILLE...GLOSTER...LIBERTY...
CROSBY...MCCOMB...TYLERTOWN...PICAYUNE...BAY ST. LOUIS...
WAVELAND...DIAMONDHEAD...GULFPORT...BILOXI...PASCAGOULA...
OCEAN SPRINGS...MOSS POINT...GAUTIER...ST. MARTIN
633 PM CST MON JAN 4 2010

...WINTER WEATHER ADVISORY IN EFFECT FROM 6 PM WEDNESDAY TO 10 AM
CST SUNDAY...

THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A WINTER
WEATHER ADVISORY FOR AN EXPECTED WINTER MIX AND EXTREMELY COLD
TEMPERATURES...WHICH IS IN EFFECT FROM 6 PM WEDNESDAY TO 10 AM CST
SUNDAY.

BY LATE WEDNESDAY NIGHT OR EARLY THURSDAY MORNING...A SURFACE LOW
WILL START TO DEVELOP OVER THE NORTHWESTERN GULF. THIS WILL CAUSE
TEMPERATURES TO WARM SLOWLY WITH MOISTURE INCREASING ACROSS THE AREA.
INITIALLY...LIGHT TO MODERATE SHOWERS WILL BE POSSIBLE BUT BY
LATE THURSDAY MORNING...A VERY COLD AIRMASS WILL BEGIN TO PUSH
INTO THE REGION. RAIN WILL BEGIN TO CHANGE OVER TO SLEET AND THEN
SNOW THURSDAY MORNING FOR AREAS IN SOUTHERN MISSISSIPPI ALONG
WITH THE FELICIANAS AND POINT COUPEE PARISH. BY THURSDAY AFTERNOON
AREAS ALONG AND NORTH OF THE 10/12 CORRIDOR WILL LIKELY SEE A MIX
OF RAIN...SLEET...AND SNOW. AT THIS TIME WE ARE NOT EXPECTING MUCH
IN THE WAY OF ACCUMULATION BUT A LIGHT DUSTING TO HALF AN INCH OF
ACCUMULATION ON GRASSY AREAS WOULD NOT BE OUT OF THE QUESTION.

ALL OF THE MOISTURE WILL MOVE OUT OF THE AREA BY THURSDAY EVENING
AND THEN THE GREATER ISSUE ARRIVES...VERY COLD TEMPERATURES. AN
ARCTIC AIRMASS WILL CONTINUE TO MOVE IN AND REMAIN OVER THE AREA
FROM THURSDAY NIGHT THROUGH SUNDAY. THIS AIRMASS IS ASSOCIATED
WITH NEAR -40 DEGREE TEMPERATURES IN THE INTERIOR OF CANADA. WITH
A NICE SNOW PACK ACROSS THE UPPER AND CENTRAL PLAINS AS WELL AS THE
UPPER AND MID MISSISSIPPI VALLEY THE AIRMASS WILL NOT MODERATE
CONSIDERABLY. THE AIRMASS IS EXPECTED TO BRING VERY COLD
TEMPERATURES TO THE AREA THAT COULD BE COMPARABLE TO THE ARCTIC
OUTBREAK OF EARLY FEBRUARY 1996...BUT NOT AS LOW AS THOSE
EXPERIENCED DURING THE 1985 AND 1989 ARCTIC OUTBREAKS. MULTIPLE
NIGHTS WITH LOWS IN THE TEENS WILL BE POSSIBLE ACROSS SOUTHERN
MISSISSIPPI AND PORTIONS OF SOUTHEAST LOUISIANA THAT ARE GENERALLY
NORTH OF THE 10/12 CORRIDOR. ACROSS THE SOUTHSHORE...LOWS COULD
DROP TO INTO THE LOWER TO MID 20S FOR MULTIPLE NIGHTS. THE COLDEST
TEMPERATURES ARE CURRENTLY FORECAST TO OCCUR SATURDAY MORNING WITH
LOWS RANGING FROM 13 NEAR MCCOMB TO 23 AT GALLIANO. EVEN THOUGH IT
IS NOT FORECAST RIGHT NOW...THIS AIRMASS DOES HAVE THE POTENTIAL
TO CAUSE LOWS THAT COULD BOTTOM OUT IN THE SINGLE DIGITS ACROSS
ISOLATED LOCATIONS IN SOUTHERN MISSISSIPPI AND MAYBE INTO THE
TEENS AROUND THE NEW ORLEANS METRO.

THESE TEMPERATURES COULD BECOME LIFE THREATENING AND AT THE VERY
LEAST HAZARDOUS TO PROPERTY. RESIDENTS SHOULD MAKE PREPARATIONS
FOR EXTREMELY COLD TEMPERATURES NOW.

TO PREVENT FREEZING AND POSSIBLE BURSTING OF OUTDOOR PIPES...
PIPES SHOULD BE WRAPPED...DRAINED...OR ALLOWED TO DRIP SLOWLY.
THOSE THAT HAVE IN-GROUND SPRINKLER SYSTEMS SHOULD DRAIN THEIR
SYSTEMS...OR COVER ANY ABOVE-GROUND PIPES TO PROTECT THEM FROM
FREEZING.

PETS ARE ALSO SUBJECT TO THE EXTREME COLD. KEEP PETS INDOORS AS
MUCH AS POSSIBLE. IF THIS IS NOT POSSIBLE...MAKE SURE OUTDOOR
PETS HAVE WARM DRY SHELTER...AND PROVIDE SUFFICIENT FOOD AND
FRESH UNFROZEN WATER.

BE PARTICULARLY CAREFUL WITH PORTABLE HEATERS...THERE IS A DANGER
OF FIRE OR POISONOUS FUMES. MAKE FREQUENT CHECKS ON THE ELDERLY.
MAKE SURE THEIR FURNACES ARE WORKING AND HEATING THE HOUSE
PROPERLY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY MEANS THAT PERIODS OF SNOW...SLEET...OR
FREEZING RAIN WILL CAUSE TRAVEL DIFFICULTIES. BE PREPARED FOR
SLIPPERY ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING.

&&

$$

CAB

It does appear strange, especially when one considers the NWS offcie that is issuing the statement. This office is usaull VERY conservative in their forecasting. So, with that said, they have to be very certain of their confidnce in forecasting this rare cold outbreak and winter precipitation event.

[Janie2006]

^^ I've no doubt of the arctic airmass, however I'm still not ready to bite on the wintry precip solution. The timing has to be just right in these parts. I want a few more model runs under my belt first.

[Kennethb]

I think Slidell issued their WWA early more to alert folks with emphasis of impending cold and not just precip. Still to early to pinpoint where wintry precip will occur.

[Brent]

Total QPF:

[Jag95]

I've been wondering about why the NWS is forecasting snow in southern MS and LA with the models showing the 850-700mb freezing line well north of the coast. Any chance they're thinking the cold air will be deeper than the models are showing? Maybe, at least to my untrained eye. 12 hours ago, the NAM showed the 0Z 0C line well north of Lake Charles and Corpus Christi. The actual 700mb temps at 0Z were below freezing at both locations. Just doing a little -removed- here so correct me if I'm wrong.

http://weather.unisys.com/upper_air/skew/index.html

[Brent]

Total QPF, quite similiar to the NAM:

[CrazyC83]

It does appear strange, especially when one considers the NWS offcie that is issuing the statement. This office is usaull VERY conservative in their forecasting. So, with that said, they have to be very certain of their confidnce in forecasting this rare cold outbreak and winter precipitation event.

Shouldn't it be a Winter Storm Watch if they need to issue it this early?

[hurricanedude]

they dont see winter precip exceeding advisory criteria...so why issue a watch?

[RNGR]

if the models dont change theres not going to be any snow within like 40 miles of the gulf coast. i havent seen any models with the freezing line or proper thickness in place for that to happen. the low temperatures will occur after the front passes.

[RNGR]

this pretty much sums it up:
medium range graphic from Jackson MS

[attallaman]

this pretty much sums it up:
medium range graphic from Jackson MS

So from this map I won't see any snow then, just cold rain. Any chance that snow line could move further S?

[RNGR]

so from this map I won't see any snow then, just cold rain. Any chance that snow line could move further S?

I really doubt it. with the gulf low so close to the coast it seems very unlikely to me that snow will fall given the warm(ish) water not too far away and warm air being pulled up from the south and around the low. could be some MAJOR ice problems though with wet roads and lows in the lower 20's and upper teens.

[attallaman]

so from this map I won't see any snow then, just cold rain. Any chance that snow line could move further S?

I really doubt it. with the gulf low so close to the coast it seems very unlikely to me that snow will fall given the warm(ish) water not too far away and warm air being pulled up from the south and around the low. could be some MAJOR ice problems though with wet roads and lows in the lower 20's and upper teens.

So no snow but still have to be worried about ice on bridges and the roads?

[CYCLONE MIKE]

I agree Rngr. I dont know what they are seeing to issue that either. Like someone else said maybe just because of the cold temps But if that were the case you think they would do like all the offices in TX and just issue special weather statements regarding that. Our forecast as of now is rain likely thursday with highs in upper 40's and clear thursday night lows near 20. I guess there could be a chance the system slows a little or something just as the cold arrives and gives us a couple of hours of mix. Also as mentioned they have been very conservative on this cold since last week.

[Brent]

I wasn't aware a winter weather advisory was issued for cold. It's very bizarre to me and makes no sense(not to mention being issued so early, ours are short fuse, usually only issued 12-24 hours before the event).

I really would be surprised to see snow on the coast. Wouldn't rule it out but looks doubtful.

[Stormcenter]

As I've said before we all know that all of the past "major" Winter events in the south were
rarely picked up by the models or forecasters until thet were on our door steps. So that being said
I wouldn't write off any events just yet based model outputs especially with such cold air headiing south. IMO

[timNms]

As I've said before we all know that all of the past "major" Winter events in the south were
rarely picked up by the models or forecasters until thet were on our door steps. So that being said
I wouldn't write off any events just yet based model outputs especially with such cold air headiing south. IMO

That is what I am thinking, too. Last few times we've had significant snow, local NWS ususally doesn't issue a winter storm warning until there are several inches of snow on the ground!