Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 5

[Srain]

A fairly significant high impact winter weather event is growing across the Southern tier of Gulf Coast States extending from Central/E/SE/NE Texas across Louisiana as a sharp shallow AArctic front drops S and stalls along the Gulf Coast. There is growing concern that a Coastal Low will develop along the Middle Texas Coast and slowly migrate ENE toward LIX increasing the chance of over running precip and a high impact event f4om a societal stand point across portions of Central and E Texas into Louisiana.areas along and N of the I-10 and I-20 Corridor could see significant icing. Further N in the colder sector, signicant snow may fall across potions of Oklahoma into Arkansas and the Tennessee Valley Region on E toward Birmingham and Atlanta. As the Coastal low strengthens on Tuesday, significant icing in the range of .50 to near 1 inch amounts maybe possible across Louisiana, Mississippi, Alabama and Georgia.

 

PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
413 AM EST MON FEB 10 2014

VALID 12Z MON FEB 10 2014 - 12Z THU FEB 13 2014

...SOUTHERN PLAINS/LOWER MISSISSIPPI VALLEY TO SOUTHEAST/MID-ATL
STATES...

A HIGH SOCIETAL IMPACT WINTER STORM IS APPEARING MORE AND MORE
LIKELY FOR THE FIRST PART OF THE WORK WEEK ACROSS THE SRN TIER OF
THE COUNTRY AND THEN PROCEEDING POTENTIALLY UP THE EAST COAST BY
MIDWEEK.

A VERY COMPLEX UPPER PATTERN WITH SPLIT FLOW REGIME REMAINS QUITE
ACTIVE ACROSS THE COUNTRY... WHILE A MAMMOTH DOME OF SURFACE
ARCTIC HIGH PRESSURE CONSUMES THE ERN TWO-THIRDS OF THE COUNTRY.
AN IMPRESSIVE AND DYNAMIC IMPULSE NEAR THE NRN ROCKIES WILL GLIDE
ALONG THE NRN STREAM AND REACH THE MID MS VALLEY ON MON.
MEANWHILE... THE LAST SHORT WAVE FROM THE PAC TROPICAL PLUME WILL
ADVANCE DOWNSTREAM ALONG THE ACTIVE SRN BRANCH AND TRACK FROM
CENTRAL CA TO THE FOUR CORNERS REGION. THE OVERALL CONFLUENT
UPPER-LEVEL FLOW AHEAD OF EACH FEATURE AND UPPER VORTEX OVER
ONTARIO WILL LOCK IN A MAMMOTH AREA OF SURFACE HIGH PRESSURE
ACROSS THE MIDWEST... WHILE A QUASI-STATIONARY BOUNDARY SETS UP
NEAR THE WRN/CENTRAL GULF COAST. ENOUGH FORCING ALOFT IN ADVANCE
OF THE SRN STREAM IMPULSE WITH INCREASING GULF OF MEXICO MOISTURE
ADVECTION WILL OVERRUN AND SURGE INTO THE FRESHLY RE-ESTABLISHED
COLD SECTOR FOR A STREAK OF LIGHT SNOW FROM SERN KS/ERN OK THROUGH
AR... WHILE RAIN TRANSITIONS OVER TO FREEZING RAIN FROM EAST AND
CENTRAL TX/NRN LA INTO NRN/CENTRAL MS/AL. THE GUIDANCE HAS
NARROWED THE SPREAD SOME DESPITE THE TOUGH SPLIT FLOW PATTERN AND
WPC GENERALLY FOLLOWED A COMPROMISE/BLEND OF THE 00Z GFS AND
ECMWF... WITH THE GREATEST ICE ACCUMULATION THREAT FROM SHV TO
BHM. 

THE FORECAST GETS MORE COMPLICATED WITH THESE TWO FEATURES ALOFT
ALONG WITH FURTHER UPSTREAM DYNAMICS ON TUES. THE NRN STREAM
IMPULSE TRACKS FROM MID MS VALLEY TO THE NORTHEAST COAST... WHILE
THE SRN STREAM SHORT WAVE TRACKS ACROSS TX TO THE LOWER MS VALLEY.
THE SLIGHT BACKING IN THE FLOW ALOFT IS DUE TO RIDGE AMPLIFYING
OFF THE SOUTHEAST COAST AND PAC DYNAMICS MOVING INTO THE PAC NW ON
MON BEFORE DIGGING DOWN THE FRONT RANGE OF THE ROCKIES INTO THE
CENTRAL PLAINS. THUS THE GENERALLY SUPPRESSED PRECIP SHIELD ON MON
WILL BEGIN TO EXPAND AND LIFT TOWARD THE SRN APPALACHIANS AND
SOUTHEAST... WHILE THE UPSTREAM DYNAMICS CAPITALIZE ON THE
EXISTING FRONTAL ZONE TO POSSIBLY INDUCE A WAVE OF LOW PRESSURE
NEAR THE CENTRAL GULF COAST BY WED MORNING. NEEDLESS TO SAY... IF
YOU ARE CONFUSED... YOU CAN IMAGINE THE REMAINING FORECAST SPREAD
WITH THE OPERATIONAL AND ENSEMBLE GUIDANCE. WPC STAYED VERY CLOSE
TO THE COMPROMISE OF THE 00Z GFS AND ECMWF FOR QPF AMOUNTS AND A
BLEND OF THESE TWO WITH THE 21Z/09 SREF MEAN FOR PRECIP TYPE. AN
IMPRESSIVE AXIS OF ICING WITH SOME SNOW IS EXPECTED ON THE
NRN/NERN FRINGE OF THE PRECIP SHIELD. THIS IS ESPECIALLY TRUE EAST
OF THE APPALACHIANS OR ACROSS THE SOUTHEAST... AS A 1030+ SURFACE
RIDGE DAMS. EXPECT POSSIBLE .10 TO MAYBE .50 INCH ICING FROM ERN
TX THROUGH NRN LA INTO CENTRAL MS EARLY IN THE PERIOD. THEN THE
ACTION SHIFTS ACROSS NRN/CENTRAL GA INTO MUCH OF SC AND MOST OF NC
WITH 2 TO 4 INCHES OF SNOW AND POSSIBLY THE BEGINNING OF A
PARALYZING ICE STORM ACROSS CENTRAL SC INTO NERN GA.

THEN FINALLY ON WED... THE DIGGING UPSTREAM DYNAMICS OVER THE
CENTRAL PLAINS WILL RAPIDLY CATCH UP WITH THE SRN STREAM DYNAMICS
TO POTENTIALLY PHASE OVER THE SERN PORTION OF THE COUNTRY. THIS
WILL ALLOW A SIGNIFICANT INCREASE IN MOISTURE ADVECTION FROM THE
GULF OF MEXICO AND ATLANTIC TO INTERACT WITH THE DEVELOPING
COASTAL LOW ALONG THE SOUTHEAST COAST... WHILE ONE OF THE MORE
IMPRESSIVE CONFLUENT ZONES ALOFT KEEPS THE ARCTIC AREA OF HIGH
PRESSURE ENTRENCHED OVER THE EAST. A TRUE BAROCLINIC LEAF PRECIP
SHIELD WILL EVOLVE FEATURING CONTINUED ICING FROM EAST OF ATL
TOWARD CAE THEN SHIFTING NORTH TOWARD RDU AND A VERY HEALTHY
DEFORMATION ZONE OF BANDING SNOWFALL FROM SWRN NC/NWRN SC NEWRD TO
SWRN/CENTRAL VA BEFORE POSSIBLY FLIRTING WITH THE DC/BALT METRO
AREAS. THE ICE ACCUMULATIONS REMAIN POSSIBLY PARALYZING IF NOT
HISTORICAL WITH ADDITIONAL .50 TO .75 INCH AXIS FROM AHN TO CAE TO
RDU AND 8 TO 10 INCHES OR SNOW FROM AVL/GSP TO ROA/LYH/CHO. WPC
CONTINUED THE COMPROMISE OF THE GFS/ECMWF WITH SUPPORT FROM THE
SREF MEAN... THOUGH MUCH MORE OF THE ENSEMBLE SUPPORT IS BEGINNING
TO CLUSTER CLOSER TO THE ECMWF ON A FULL FLEDGED PHASED COASTAL
WINTER STORM.
 

[bubba hotep]

The temp has been slowly dropping all morning and we are finally down to 32.  Now to see if we warm up today or will the cold over perform?

[bubba hotep]

FWD seems to be giving up on the thought that temps will warm and will also be considering an upgrade later today:

 

FXUS64 KFWD 101658
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1058 AM CST MON FEB 10 2014

.UPDATE...
THE FREEZING LINE CONTINUES TO SLIDE SLOWLY SOUTH AND WAS NEAR A
BROWNWOOD...STEPHENVILLE...FORT WORTH TO BONHAM LINE AT 10 AM.
ALTHOUGH THE DRIZZLE HAS BEEN LIGHT AND SPOTTY IT HAS BEEN ENOUGH
TO CAUSE SOME ICING CONDITIONS GENERALLY NORTH/NORTHWEST OF AN
EASTLAND...DENTON...TO BONHAM LINE. THE INITIAL THINKING WAS THAT
TEMPERATURES MIGHT MANAGE TO WARM A FEW DEGREES TODAY WHICH WOULD
KEEP MOST OF THE AFTERNOON PRECIP FROM FREEZING. HOWEVER...CURRENT
ANALYSIS AND MODEL OUTPUT SHOWS CONTINUED COLD AIR ADVECTION AND
NEAR STEADY TEMPERATURES THROUGH THE AFTERNOON. THEREFORE...WE
HAVE DECIDED TO EXTEND THE CURRENT FREEZING RAIN ADVISORY FOR THE
NORTHWEST ZONES THROUGH TUESDAY AFTERNOON.

THE ADVISORY WILL LIKELY NEED TO BE EXPANDED TO INCLUDE MUCH OF
NORTH TEXAS TONIGHT THROUGH TUESDAY SINCE TEMPERATURES WILL FALL
A FEW MORE DEGREES OVERNIGHT AND PERIODS OF DRIZZLE WILL CONTINUE.
AT THIS POINT IN TIME WE DO NOT FEEL AMOUNTS WILL BE ENOUGH TO
WARRANT A WARNING. HOWEVER...SINCE LARGE SCALE LIFT IS PROGGED TO
INCREASE OVERNIGHT/TUESDAY...THERE IS A CHANCE OF A BRIEF PERIOD
OF SLIGHTLY MORE PRECIPITATION WITH SOME LIGHT SNOW POSSIBLE IN
THE NORTH AND A MIX OF FREEZING RAIN AND SLEET FARTHER SOUTH.

WE WILL LOOK AT MORE DATA BEFORE MAKING ANY FINAL DECISIONS ON
AREA AND VALID TIME OF ANY TYPE OF NEW ADVISORY OR WARNING.

[Quixotic1]

Ice pick needed to get into the truck. 28 and mist

[bubba hotep]

Ice pick needed to get into the truck. 28 and mist

 

We are down to 31.4, expecting to start seeing some icing here soon since we still have heavy mist / fog.

[msp]

44/43 here.  going to be real close to getting some zr mixing in tonight and/or tomorrow.  wouldn't shock me to see another WWA for the northern few counties in the HGX FA.

[DoctorMu]

41/39 now w/ freezing line just N of Waco.

 

We need some Karma payback for 2 duds and 1 small overperformer...that led to a few bang-ups on the highway.

[bubba hotep]

Pretty much everything around here above the ground has a glaze on it.  Looks like the morning commute could be a pain with temps dropping into the mid-20s, even if we just continue to get this mist/fog combo and nothing heavier.

[Quixotic1]

Pretty much everything around here above the ground has a glaze on it. Looks like the morning commute could be a pain with temps dropping into the mid-20s, even if we just continue to get this mist/fog combo and nothing heavier.

According to IMBY, it is 26. Everything but the ground is coated in ice.

I'm wondering if we will see anything heavier. Nothing on the radar in the southern plains loop except near the panhandles.

Edit: wrecks all over the place. NDT shutdown in both directions near eldorado.

[bubba hotep]

According to IMBY, it is 26. Everything but the ground is coated in ice.

I'm wondering if we will see anything heavier. Nothing on the radar in the southern plains loop except near the panhandles.

Edit: wrecks all over the place. NDT shutdown in both directions near eldorado.

 

We are at 29, IMBY, with heavy mist.  There is ice on everything with some really nice icicles forming on street signs and what not.  The RAP seems to want to develop an area of enhanced precipitation across DFW tomorrow as the best forcing rolls through.  The RAP doesn’t seem very accurate but does seem to be good at picking up on trends.  So someone between I-20 and the Red River might see something interesting tomorrow

 

ETA: FWD with an update

 

.UPDATE...

LIGHT ICING AND GLAZING FROM FREEZING DRIZZLE HAS CONTINUED TO

MOVE SOUTHEAST INTO MUCH OF NORTH TEXAS...INCLUDING SECTIONS OF

THE METROPLEX THIS EVENING. UNFORTUNATELY...NUMEROUS ACCIDENTS

HAVE BEEN REPORTED ACROSS MANY OF THESE AREAS...SO WE CAUTION NOT

TO DRIVE TONIGHT UNLESS NECESSARY. MAIN IMPETUS FOR THIS UPDATE

IS THE COMPLEX FORECAST THAT IS IN STORE TONIGHT THROUGH EARLY

TUESDAY EVENING. RIGHT NOW...WEAK ISENTROPIC UPGLIDE OVER THE

FRONTAL INVERSION IS RESULTING IN DRIZZLE AND FREEZING DRIZZLE

ACROSS THE REGION. EVERYONE SHOULD SEE THINGS TRANSFORM OVER TO

FREEZING DRIZZLE DURING THE OVERNIGHT HOURS.

OUR UPPER DISTURBANCE ARRIVES BY MID MORNING TUESDAY AND WILL

ALLOW DEEPER MIXING THROUGH 700MB FOR A TRANSFORMATION OF

FREEZING DRIZZLE OVER TO A MIX OF FREEZING RAIN...SLEET...AND

POSSIBLY A COLD RAIN OVER THE SOUTHEAST. TOWARD THE RED RIVER

VALLEY...EVEN A MIXING OF LIGHT SNOW CAN BE EXPECTED. DUE TO THE

TRANSITION TUESDAY MORNING...WE HAVE PUT EVERYONE INTO A WINTER

WEATHER ADVISORY DUE TO THESE CHANGES AND HAVE MOVED UP THE START

TIME TO NOW DUE TO TEMPERATURES BEING SLIGHT COLDER THAN

PREVIOUSLY EXPECTED.

ALL WINTER PRECIPITATION SHOULD END EARLY TUESDAY EVENING...BUT

IT WILL REMAIN COLD AND ANY PUDDLES ON THE GROUND WILL LIKELY

REFREEZE AND CAUSE SOME SLICK SPOTS EARLY TUESDAY NIGHT INTO

WEDNESDAY MORNING AS WELL. AFTERWARD...A NICE WARM UP IS IN STORE

FOR NORTH TEXAS WITH 50S...60...AND LOWER 70S RETURNING FOR

THURSDAY AND FRIDAY.

[Srain]

Morning Update from Jeff:

 

Freezing rain advisory remains in place for today for the northern 1/3^rd of the area.

 

Strong short wave clearly noted over New Mexico spreading lift toward the region this morning. 700am surface temperatures are above freezing at all locations across SE TX however surface dewpoints have fallen below freezing as far south as northern Harris County under dry air advection overnight as the light rainfall and drizzle ended. While surface temperatures have been unable to fall to below freezing under the influence of cold air advection…the advection of drier low level air southward sets the stage for enough room for some evaporative cooling as precipitation begins to onset again later this morning. With surface temperatures in the 33-35 degree range north of HWY 105 it will not take much cooling to get the advisory area to freezing. While dewpoints further southward are at freezing even into Harris County, do not think evaporative cooling will be enough to reduce the surface temperature to freezing…hence all liquid and no ice.

 

P-type:

Impressive warm layer remains in the mid levels with 850mb temperatures on the order of the mid and upper 40’s suggesting this is a freezing rain profile. With that said the slightly drier air might result in just enough mid level cooling to produce some sleet mixture as far south as HWY 105 this afternoon. Not confident that is going to happen and this would really not change the impacts in the advisory area any.

 

Accumulation:

Rainfall amounts look light on the order of .05-.10 of an inch in the advisory area which would equate to about 50% of that of ice accumulation especially since surface temperatures are so marginal. Looks like bridges and overpasses could be the issue, but time od ay with a slightly increased solar angle does support some radiation getting through the clouds and bring absorbed by the bridges…which may just be enough to keep them wet instead of ice covered. Bigger concern is after sun set with light freezing rain still falling and temperatures falling into the 29-31 degree range…which could result in fairly quick icing over of bridges in the advisory area. Still think the best chances for ice accumulation will be east of I-45 and more likely around Lake Livingston.

 

For Metro Houston: all precipitation will remain liquid and do not expect ice formation in this area. Any wet spots on bridges and overpasses overnight could freeze as temperatures fall below freezing Wednesday morning.

 

Extended:

The “great” warm up begins in earnest Thursday into the weekend as southerly Gulf flow becomes established and the upper air pattern over the US more zonal keeping any arctic air trapped in Canada or across the eastern US. Will need to keep an eye on dewpoints over the cold nearshore waters which could spread low clouds and fog inland as earlier as Friday and lasting into the weekend making it more cloudy than what model guidance is suggesting.

 

 

 

 

[Srain]

Freezing drizzle now reported in Cedar Park (Bexar County) in the San Antonio area. Also numerous reports of treacherous roadways and many accidents across the San Angelo area.

[msp]

36/27

 

temp actually rose last hour.  no precip at all here, but i gotta imagine the surface wet bulb temp is gonna be pretty close to freezing when it begins later today.

[Quixotic1]

Getting dry slotted!  argh.

[aggiegeog]

Raining pretty hard, can't tell if sleet mixed in from office window, with temp 32/29.

[msp]

Raining pretty hard, can't tell if sleet mixed in from office window, with temp 32/29.

 

just a darn cold rain as far as i can tell.   no sleet mixed in at my place in south CStat.  CLL reporting 35/32 last hour

[aggiegeog]

We have been in a light to moderate freezing rain for a while now and it looks like we will stay in frozen precip for the remainder of the day into tonight. Current temp 32/30 with icles on the trees.

[Quixotic1]

Snowing oh so faintly now. 

[bubba hotep]

This is probably the end for us… some sleet today and now a very weak snow/sleet mix to close it out.  Outside of that surprise 1" of snow this last cold snap was really wasted

 

The long range signals don’t look so great and climo isn’t kind in these parts and it will start bringing the pain with the quickness. 

[aggiegeog]

Ice on elevated surfaces here, roads are just wet except when the sleet comes down heavily. Looks like here north of Lindale we are getting a break right now before the next band comes in from the west.

[Quixotic1]

This is probably the end for us… some sleet today and now a very weak snow/sleet mix to close it out. Outside of that surprise 1" of snow this last cold snap was really wasted

The long range signals don’t look so great and climo isn’t kind in these parts and it will start bringing the pain with the quickness.

My very thoughts, though I've seen events in March. 2002. 1989.. Wouldn't count on them though.

Now I can spend time on more important things like "how does Waco have freeze numbers like Mckinney, yet still has more 100 degree days than DFW?"

[Srain]

Some very interesting facts from HGX when we have cold winters and the correlation to the sensible weather we can get in the Summer.

[Srain]

Some very interesting facts from HGX when we have cold winters and the correlation to the sensible weather we can get in the Summer.

[bubba hotep]

The GFS / GEFS are hinting that winter might not be over just yet... the last couple of runs want to send down another cold shot

 

 

[Srain]

Foggy mornings look to be the theme into next week with those cool shelf waters and a flow off the Gulf. There is still rather strong indications that a strong front will arrive late next week as a deep trough develops across the Western and Central US and a Ridge is in place across the East. Today marks the anniversary of the biggest recorded snow storm in Houston of 20 inches set in 1895.

[bubba hotep]

Foggy mornings look to be the theme into next week with those cool shelf waters and a flow off the Gulf. There is still rather strong indications that a strong front will arrive late next week as a deep trough develops across the Western and Central US and a Ridge is in place across the East. Today marks the anniversary of the biggest recorded snow storm in Houston of 20 inches set in 1895.

I wonder what 20" of snow would do to Houston today? That would be crazy to see!

[DoctorMu]

The fog is cool.  Unless some significant precip (which we need) comes from it, though I'm not a fan of the onshore.  There will be plenty of it during funderstorm season.  That's an awesome pic of the snow.  Ok, Ok, I'm a bit jaded because of the 3 duds and the spurt of sleet and mini-snow...while being FB spammed by family/cousins with glorious pictures of deep snow and drifts in the east coast..with days off....and Aggies careened right and left off tiny ice patches into stable and moving objects... 

 

President's Day Miracle?   Unlikely, but will keep the glass 1/100 full...

[bubba hotep]

DROUGHT INFORMATION STATEMENT
NATIONAL WEATHER SERVICE FORT WORTH TX
1130 PM CST SUN FEB 16 2014

...WITH DRY START TO 2014...DROUGHT CONDITIONS SLOWLY RE-EMERGE...

--------------------------------------------------------------------

SYNOPSIS...

WITH A STATEWIDE AVERAGE OF ONLY 0.39 INCHES OF (WATER EQUIVALENT)
PRECIPITATION DURING THE MONTH...JANUARY 2014 RANKED AS THE 5TH
DRIEST ON RECORD. IT WAS THE DRIEST JANUARY FOR THE STATE SINCE 1971
(WHICH IS THE DRIEST JANUARY ON RECORD). THE DRY SPELL HAS CONTINUED
INTO FEBRUARY...

[Ed Lizard]

I'm waiting on FUNderstorm season.  Cold near shore waters after a cold Winter, can't cound on insolation to break the cap, will need systems that track to the South, and negatively tilted systems usually produce a weaker cap.  Mainly a SETX issue.  I am not aware of a correlation of a cold Winter to FUNderstorms further North, except cooler Gulf probably means lower dews.

 

 

Still a little sad.  A weak cap, and temps rising until the cap breaks, tend to wind up with more available convective potential energy.  And I love watching a blow up on an otherwise mostly sunny day...

[DFWWeather]

Folks, don't put away your winter coats just yet! Old Man Winter doesn't appear to be quite done with us yet...