Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 4

[wxmx]

I'll probably be in the bullseye temp anomaly wise with the 2nd impulse of energy rounding the next long wave passage... and close to the lowest mean temp for my location...but even then, it looks like it will stay above freezing... maybe some very light snow close by in the mountains to my south.

[Srain]

Morning update from Jeff:

Widespread rainfall will develop this evening and continuing into Tuesday.

Warm front with all its associated weather (fog, drizzle, and light rain) currently extends from near Victoria to Wharton to San Luis Pass. South of the front temperatures have increased to 71 at Bay City versus 48 at Caldwell. Fog and drizzle are noted across nearly the entire area. Warm front will make very slow northward progress today possibly reaching I-10 by late afternoon while increasing upper level lift from a short wave ejecting out of the mean SW US trough moves into the region this afternoon. Expect to see widespread light to moderate rainfall develop with a few heavier showers. Could see a thunderstorm or two near the warm front this afternoon as the lift increases, but the chance is fairly low given near zero instability.

Main event is expected tonight as another strong cold front sags into the area. Moisture profiles on the CRP and BRO 12Z soundings were in the 1.3-1.5 inch range on the PWS and expect this moisture advection to progress up the coast and into SE TX this afternoon. This does support heavy rainfall given the high moisture parameters for this time of year, but lack of any significant surface instability should greatly reduce the threat for organized thunderstorms producing very heavy rains.

General widespread rainfall with embedded heavy downpours can be expected tonight with storm totals of 1-2 inches NE of a line from Brenham to Angleton with isolated totals near 3 inches. SW of this line totals will average .5 to 1 inch.

Temperature today will slowly rise to the mid to upper 60’s south of the warm front and remain steady of slowly rise into the mid 50’s north of the boundary. Cold front tonight will knock temperatures back into the 40’s and they will remain in the 40’s on Tuesday under gusty NW winds, clouds, and lingering rainfall.

Cold front will slowly sag off the coast on Tuesday with drier low level air mass filtering southward. Large swath of rainfall should progress to the coast and possibly offshore, but active southern stream jet in combination with main axis of the upper level trough remaining west of the area over N MX will continue thick clouds and potential rain chances Wed-Thurs. Models are not and have not been handling the mid-late week pattern/forecast very well as they bounce between wet and dry. One item that is nearly certain is that temperatures will be cool to cold with lows in the 40’s and highs in the 50’s under mainly cloudy skies. As for rainfall, will keep some chance of rainfall near the coast, but it is uncertain as to how far inland rains may spread from time to time as weak disturbances translate through the SW US trough and across TX. Wed night and Thurs AM look like a possible wet period especially near the coast.

[ams30721us]

hmmm

[Ed Lizard]

I'm impressed by the idea of 1.7 to 1.8 inch PWs from both GFS and NAM for January 1st.

I tweeted NWS HGX and inquired as to how many standard deviations above normal that would be (I know they know, sometimes the AFDs will include descriptions of PW before a rain event as nearly 2 SD above normal) but they never responded.

[Srain]

Starting to see a bit more instability and elevated storms are beginning to fire suggesting a very damp and dreary New Years Eve ahead...Happy New Year Central/Western gang!

[bubba hotep]

Starting to see a bit more instability and elevated storms are beginning to fire suggesting a very damp and dreary New Years Eve ahead...Happy New Year Central/Western gang!

Happy New Year All

Looks like we might make it back into the 50's next week! 6" of snow followed by nearly two weeks of sub-50 weather, not a bad way to close out the year

[bubba hotep]

It is starting to look like this warm up will be brief for north Texas and the cold could make a return around mid-month.

[Ed Lizard]

For future reference, handy PW climatology chart by date for various radiosonde launch locations.

http://www.crh.noaa.gov/unr/?n=pw

[Quixotic1]

happy new years to all

[DoctorMu]

It is starting to look like this warm up will be brief for north Texas and the cold could make a return around mid-month.

GFS has some fun forecasting on the 12th and then keeps it real for about a week.

[Srain]

Winter Storm Watches have been hoisted for El Paso to Presidio into the Big Bend Region on E into Alpine for 4-6 inches of snow. NWS San Angelo has issued a SPS regarding a rain/snow mix extending E as far as Brownwood. NWS San Antonio/Austin now talking about the first snow of the season for the Edwards Plateau and Hill Country. NWS Houston/Galveston does mention a 20% chance of light rain on Saturday. Depending on timing and just how much the dry air at the surface can moisten up, I guess a stray ice pellet or two may not be out of the question. As always, these type events are also difficult to forecast and often come as a surprise. We'll see what the next 24 hours or so holds and just how strong the upper level low is as it ejects across W Texas.

 

HPC:

 

SHORT RANGE FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
351 AM EST WED JAN 02 2013

VALID 12Z WED JAN 02 2013 - 12Z FRI JAN 04 2013

...RATHER QUIESCENT CONDITIONS SHOULD PERSIST OVER MUCH OF THE
REMAINDER OF THE CONUS...

...ACCUMULATING SNOWS WILL FOCUS OVER THE GREAT LAKES REGION AS
WELL AS ACROSS SOUTHWEST TEXAS...

MOISTURE AS A WHOLE SHOULD REMAIN RATHER LIMITED AS A FRONTAL
BOUNDARY SINKS SOUTHWARD INTO THE GULF OF MEXICO. MUCH OF THE
MOISTURE FROM THE GULF WILL POOL NORTHWARD FOCUSING AN AXIS OF
SCATTERED RAIN SHOWERS ALONG THE IMMEDIATE GULF COAST.
HOWEVER...THE MID-LEVEL PATTERN WILL NOT BE VERY SUPPORTIVE FOR
MORE WIDESPREAD PRECIPITATION EXCEPT FOR THE FEW WEAK IMPULSES
EMERGING WITHIN THE BROADER SCALE SOUTHWESTERLY FLOW. WHILE IT
WILL NOT BE A SOAKER ALONG THE GULF COAST...SCATTERED SHOWERS ARE
FORECAST TO IMPACT THE REGION THE NEXT COUPLE OF DAYS GIVEN THE
PRESENCE OF THE STALLED BOUNDARY OVER THE CENTRAL GULF. LOOKING
FURTHER UPSTREAM...A CLOSED UPPER LOW DROPPING SOUTH TO
SOUTHEASTWARD INTO NORTHERN BAJA CALIFORNIA WILL BE THE NEXT
PRECIPITATION MAKER TO SECTIONS OF SOUTHERN NEW MEXICO AND INTO
WEST TEXAS. LOW-LEVEL TEMPERATURES ARE FORECAST TO BE AROUND
FREEZING WHICH WILL ALLOW SNOW TO FALL OVER THIS REGION BY
THURSDAY AFTERNOON. THROUGH FRIDAY MORNING...THE HPC WINTER
WEATHER DESK IS ADVERTISING A FEW INCHES OF SNOW WITH POCKETS OF
SLIGHTLY HEAVIER AMOUNTS CLOSER TO THE RIO GRANDE RIVER.

LOOKING TO THE NORTH...AN UPPER RIDGE ANCHORING THE NORTHWESTERN
STATES WILL ALLOW AN EXPANSIVE TROUGH TO DEVELOP OVER THE
NORTH-CENTRAL CONUS AND OUT TOWARD THE NORTHEASTERN U.S. THE
SPARSE MOISTURE PROFILES WILL LIMIT PRECIPITATION FROM THESE
IMPULSES TRACKING THROUGH THE REGION. HOWEVER...LIGHT TO MODERATE
SNOW SHOWERS ARE EXPECTED TO DEVELOP OVER THE NORTHERN GREAT LAKES
AS A FRONTAL BOUNDARY SETS UP ORIENTED WEST-TO-EAST ALONG THE
LAKES. LOW-LEVEL LIFT AIDED BY THIS FRONT COMBINED WITH FAVORABLE
WIND TRAJECTORIES ALONG THE LAKE SURFACE WILL HELP INITIATE SNOW
SHOWERS THROUGHOUT THE PERIOD. 2 TO 4 INCHES OF SNOW WILL BE
POSSIBLE THROUGH FRIDAY MORNING WITH ISOLATED HEAVIER AMOUNTS
DOWNWIND OF LAKE ONTARIO.

THE INTERMOUNTAIN WEST WILL BE DOMINATED BY A SURFACE/UPPER RIDGE
WHICH SHOULD KEEP CONDITIONS RATHER QUIET THROUGHOUT MUCH OF THE
WEEK. IDEAL RADIATIONAL COOLING EFFECTS WILL LEAD TO SUB-ZERO
OVERNIGHT LOWS ACROSS CERTAIN AREAS WHILE HIGHS ONLY REBOUND INTO
THE TEENS AND 20S. THIS SETUP WILL ALSO ALLOW OFFSHORE FLOW TO
DOMINATE THE STATE OF CALIFORNIA. HOWEVER...THE PRESSURE GRADIENT
DOES NOT APPEAR TO BE SIGNIFICANT ENOUGH TO RESULT IN A STRONG
WIND EVENT.


RUBIN-OSTER

 

PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
417 AM EST WED JAN 02 2013

VALID 12Z WED JAN 02 2013 - 12Z SAT JAN 05 2013

DAY 1...

THE PROBABILITY OF SIGNIFICANT SNOW AND/OR ICING IS LESS THAN 10
PERCENT.


DAY 2...

...WEST TEXAS / TRANS PECOS REGION...

A CLOSED LOW SEEN ON WV IMAGERY OFF THE SRN CA COAST THIS MORNING
WILL TRACK EWD ACROSS NWRN MEXICO TONIGHT...WHILE A NRN STREAM
TROUGH AXIS BEARS DOWN ACROSS THE SWRN U.S. FROM THE NORTH. THE
TWO WILL INTERACT THU INTO FRI RESULTING IN A CLOSED LOW OVER THE
SOUTHWEST. THE MODELS CONTINUE TO COME INTO BETTER AGREEMENT THIS
THIS SCENARIO AND INDICATE A SIGNIFICANT SNOW STORM FOR PORTIONS
OF WEST TEXAS / NRN MEXICO. ALTHOUGH THE UKMET IS DELAYED IN
CLOSING OFF A LOW...THERE IS GOOD CONSENSUS AMONG THE 00Z
NAM/GFS/ECMWF/CMC AND SREF/GEFS/EC ENSEMBLE MEANS AS WELL AS
RUN-TO-RUN AGREEMENT TO DISCOUNT THE 00Z UKMET. USED ROUGHLY EQUAL
WEIGHTING IN A BLEND OF THE NAM/GFS/ECMWF/SREF...NOT PUTTING TOO
MUCH WEIGHT ON THE NAM AS IT TENDS TO HAVE A COLD/WET BIAS.

DESPITE AN INITIALLY DRY ATMOSPHERE TO BATTLE...SNOW LOOKS TO
OVERSPREAD SWRN TEXAS WITH PERHAPS RAIN FOR THE LOWER ELEVATIONS
OF THE RIO GRANDE VALLEY THU MORNING...AS STRONG...DIFLUENT LIFT
ALOFT COMBINES WITH LOW LEVEL UPSLOPE FLOW IN CONNECTION TO
STRONG/COLD HIGH PRESSURE ANCHORED OVER THE PLAINS. MODEL FORECAST
SOUNDINGS INDICATE WARMING TO NEAR...BUT STILL BELOW 0 C...AT AND
BELOW 700 MB...WHICH COULD BE A TREND TOWARD SLEET MIXING IN. IN
ADDITION...THE LOWEST 10-15 KFT OF THE SOUNDING IS FCST ABOVE -10
C...INDICATIVE OF A HEAVY/HIGH DENSITY SNOW. SLR VALUES MAY
AVERAGE CLOSE TO 10:1 BUT PERHAPS A LITTLE GREATER IN THE HIGHER
ELEVATIONS. A SLIGHT RISK OF 4 INCHES WAS DRAWN FOR MUCH OF WEST
TEXAS INTO FAR SRN NEW MEXICO. A MODERATE RISK OF 4 WITH A SLIGHT
RISK OF 8 WAS DRAWN FOR THE HIGHER ELEVATIONS...ESPECIALLY INTO
THE DAVIS...GLASS AND CHINATI MOUNTAINS.

AS THE UPPER LOW BEGINS TO EJECT OUT TOWARD THE END OF DAY 2...FRI
MORNING...THE MID LEVEL JET COMING AROUND THE BASE OF THE LOW MAY
BRING IN ENOUGH DRY AIR ALOFT TO CAUSE ANY REMAINING PCPN TO FALL
AS FZDZ AS MODEL FCST SOUNDINGS INDICATE TO THE TOP OF THE
SATURATED LAYER NEAR OR ABOVE -10 C.

 

[Srain]

2012 year in review from Jeff:

 

E-mail from Jeff reviews the year 2012:

January 9:
 
Heavy rainfall, flooding and tornadoes strike SE TX. 4-6 inches of rainfall in 1-2 hours over southern Harris County leads to flooding along Brays and Keegans Bayous. Over 100 homes flooded. Tornado strikes Fort Bend County (near The Meadows) with damage to roofs in the Mission Bend area. Tornado rated EF 1. Tornado strikes the Mall of the Mainland in Texas City damaging the mall and blowing out car windows.
 
January 24:
 
Small hail accumulates on the ground in College Station from thunderstorms along a northward moving warm front

January 25:
A powerful storm system brings gusty south winds of 40-45mph to the area: Sugar Land (45mph), Wharton (45mph), Katy (45mph). Line of severe thunderstorms brings wind damage to areas north of I-10.
 
Brenham: 70mph (EF0) tornado strikes the Brenham area)
5.66 inches of rain fall in 24 hours at Austin (the greatest single day rainfall since 9-7-2000)
9.35 inches recorded 2.4 miles WNW of Bastrop
 
February 3
 
Narrow band of heavy rainfall produces 4-6 inches of rain over extreme NW Liberty and southern San Jacinto Counties
 
February 4:

6-11 inches of rain fall over Brazos and Burleson Counties with widespread flooding. College Station records 4.11 inches.
 
March 2:
 
Tornado outbreak results in 79 tornadoes across the OH valley and Gulf coast. 39 persons killed and over 500 injured
 
March 19:
A strong storm system brings strong southerly winds to the area: Victoria (44mph), Palacios (42mph).
80mph Microburst strikes George West in Live Oak County producing widespread wind damage 1.5 miles long by 2.5 miles wide.

March 20-21:

8-10 inches of rainfall occurs along the Sabine River from east of Beaumont to central Louisiana producing significant flooding.
College Station shatters daily rainfall record for March 20th of 1.65 inches after recording 2.38 inches.
 
March 29
 
Hail of varying sizes fell over McAllen, TX for nearly an hour driven by 70-75mph winds. Hail drifts to 6” deep with nearly every home in the city suffering damage. An estimated 200 million dollars in damage.
 
April 2:
 
Large bow echo moves across Matagorda Bay area producing 80mph winds at Port Lavaca and 69mph at Port O Connor. Wind damage was .5 of a  mile wide to 2 miles long.
 
Strong winds destroyed a mobile home in Hungerford in Wharton County.
 
April 3:

Cluster of destructive tornadoes move across the Dallas/Fort Worth metro area. Hundreds of homes damages with 20 persons injured. 110 planes at DFW airport damaged by golf ball size hail.
 
April 4:

Baseball size hail falls in Alvin, TX breaking home windows and shattering car windows
 
 
April 15:

Strong south winds push tide levels 1.5-3.0 feet above normal along the upper TX coast resulting in minor coastal flooding.
 
April 16:
 
Large high precipitation supercell produces 10-12 inches of rainfall in a few hours over Portland and Gregory in San Patricio County. Emergency Manager recorded 15.0 inches of rainfall. 496 homes flooded several with over 3 feet of water. 80% of the town of Gregory flooded.
 
April 20:
 
Numerous reports of hail and wind damages across the area from a line of thunderstorms along a cold front

May 9:
Tornado strikes Weimar in Colorado County. 8 injured. Damage to schools, 65% of the town without power. 40 railroad cars overturned
 
May 10:
Large bow echo moves across the coastal bend.

96mph wind gust recorded by a MS State Storm Chase team in Corpus Christi
66mph recorded by Oil Platform in Corpus Christi Bay
53mph at Galveston
61mph at Port Aransas
65mph at Holiday Beach
49mph at Seadrift
58mph at Port O Connor
70mph at Fulghum Point
 
16 tornadoes strike S TX in 24hrs in addition to the large scale bow echo. This was a record number of tornadoes for S TX not related to a tropical cyclone landfall.
 
May 12:

Excessive rainfall in a 12 hour period from central Fort Bend County to southern Harris and northern Galveston counties results in flooding along Clear Creek and Keegans Bayou.
 
CoCoRaHS observer in Pecan Grove: 10.70 inches
Sugar Land: 9.10
Richmond: 4.06
Westbury: 6.49
League City: 5.57
Friendswood: 6.1
Richmond (Pecan Grove): 8.93
 
June 10:
Lightening sparks a large march fire in Chambers County with smoke blanketing Galveston Island and Galveston Bay
 
June 12:
Severe thunderstorms produces very strong winds of 60-70mph along I-45 from Conroe to Aldine. 161,000 residents lost power. Numerous trees downed.
 
June 25:
 
Palacios records 102 degree high temperature. This was the hottest June temperature ever recorded and the 3rd warmest temperature ever recorded at the site.
 
Galveston recorded 100 degrees only for the 8th time ever. Galveston had never recorded a June 100 degree day prior.
Victoria: 106
Angleton: 101
Corpus Christi: 105
Hobby: 102
 
June 26
 Record heat continued for 3rd day
 
Record Highs for Tuesday June 26:
College Station: 106 (broke record of 105 in 2009)
Galveston: 97 (broke record of 95 in 1875)
BUSH IAH: 105 (broke record of 104 in 2009)
Hobby: 102 (broke record of 99 in 2009)
Brownsville: 103 (broke record of 100 in 1900)
Waco: 107 (tied record of 107 in 1980)
Austin Mabry: 109 (broke record of 105 in 2009, set new all-time June record high, previous record was 108 on June 14, 1998)
Corpus Christi: 106 (broke record of 100 in 1980)
Victoria: 108 (broke record of 102 in 2009)
San Antonio: 106 (broke record of 103 in 2009)

July 9:
 
Microburst strikes San Angelo Airport. ASOS recorded wind gust to 68mph, several hangers damaged
 
July 10:

6-9 inches of rain falls over Bastrop County resulting in flash flooding  and evacuations of trapped residents
 
July 11-13:
 
A slow moving trough axis and plume of tropical moisture produces 10-14 inches of rainfall over NW Harris, Waller, and SW Montgomery Counties. Widespread flooding along Cypress Creek, Little Cypress Creek, Willow Creek, and Spring Creek. Over 200 homes are flooded across those three counties. Little Cypress Creek records its highest recorded water level surpassing the historic flooding of 1994.
 
April-August 2012:
 
Widespread record drought impact much of the central US. On August 21, 62% of the US was considered to be in moderate drought. Portions of the MS River were too low to allow vessel traffic. 1692 counties in 36 states were declared natural disaster areas as of Aug 17 with extensive crop losses through much of the plains. The remains of Hurricane Isaac brought heavy rainfall to some of the eastern parts of the drought stricken middle MS valley in early September. This was the most extensive drought since the dust bowl drought of the 1930’s. the excessive heat also result in 123 direct deaths. Exceptional drought continues throughout much of the central plains at the end of 2012.
 
August 29-30:
 
Hurricane Isaac makes landfall in SE LA producing extensive storm surge and rainfall flooding. Storm surge of 9-11 feet recorded overtopped some levees. Rainfall of just over 20 inches recorded in New Orleans. 9 US fatalities including 5 in LA. 900,000 without power. 59,000 homes damaged in SE LA mostly from storm surge and rainfall flooding. 2 billion dollars in damages
 
September 28-30:

10.55 inches of rainfall recorded in Grapeland in Houston County
 
October 29
Post tropical cyclone Sandy “Superstorm Sandy” made landfall along the southern New Jersey coast bringing record storm surge values to New Jersey and New York. Damage estimated at over 65.6 billion dollars making Sandy the second costliest hurricane only behind Katrina. 131 fatalities in the US (253 along the path). 24 US states affected with over 8 million persons without power. New York subway system and tunnels flooded with seawater for the first time. On Long Island alone nearly 100,000 homes were damaged or destroyed with more than 2,000 either destroyed or washed away. Sandy set numerous storm surge and lowest barometric pressure records all across the NE and mid Atlantic states.
 
November 19:
Moderate to severe drought conditions re-develop across SE TX after being nearly drought free in July. Early and mid 2012 rainfall surpluses are reduced to zero due to a dry October and November period.
 
November 22:
Thick fog with visibilities less than 100 feet resulted in a 100+ vehicle pile-up on I-10 in Chambers County. Over 50 persons injured and 2 fatalities.
 
December 19:
Strong winds produce widespread blowing dust over W TX. It was the longest duration dust storm since 1977. Visibilities of less than .25 of a mile at times resulted in a significant chain reaction accident with over 100 vehicles involved
 

From an airplane of Lubbock
 
 
December 20:
Strong winds impact the area behind a powerful cold front
N Jetty: 61
Palacios: 48
Sugar Land: 46
Conroe: 47
College Station: 43
Eagle Point: 40
 
December 25
Severe weather including tornadoes impact SE TX (Houston and Trinity Counties)
 
EF3 rated tornado with winds near 150mph impacts Houston County destroying several buildings.
 
Strong winds impact the entire region
BUSH IAH: 51
College Station: 54
Tomball: 46
Wharton: 45
Conroe: 49
Hobby Airport: 56
Brenham: 46
Bay City: 44
Galveston: 47
Lake Jackson: 46
Pearland: 51
Palacios: 53
Huntsville: 52
Bay City: 39
Victoria: 48
 
Snow falls over N TX including the D/FW metro area.

[Srain]

Light sleet/rain mix being report just NW of Houston at this hour. Jeff also reports IP/-rn mix @ Transtar as well HWY 290/610 Loop.

[Srain]

Morning update from Jeff:

 

Classic winter weather pattern in place over TX this week with cold air flowing southward from the north being overrun by moist SW flow aloft.
 
Cloudy, cold, and at times wet pattern will remain in place through the weekend as an active sub-tropical jet stream on the south side of a mean southwestern US trough overtops a cold surface air mass over TX. A cold front crossed the region early Tuesday morning producing a period of very heavy rainfall of 3-5 inches right along the coast from Brazoria County to Jefferson County. Galveston recorded at record 4.01 inches of rainfall making it the wettest New Years Day ever for that location. Most of the rest of the area saw much less rainfall with totals averaging in the .5 to 1.0 inch range. Cold front has made steady progress off the coast and well into the Gulf waters however a warm and moist upper level flow is pouring NNE over the surface cold dome resulting in a large stream of clouds from the eastern Pacific across much of TX. A review of the morning soundings from BRO, CRP, LCH, and FWD shows much wetter profiles from Corpus southward with significant amounts of dry air located just north of SE TX in the N TX and N LA soundings. The LCH sounding  had a dry layer from roughly 850 to 700mb. While the radar is highly active only small amounts of rainfall are able to pass through the dry layer and reach the ground. Surface observations indicate rain is reaching the ground mainly southwest of a line from High Island to Hobby Airport to Columbus. Given the upstream look at the radar (widespread coverage), suspect the mid level dry layer will shrink some today allowing a few more locations to pick up measurable rainfall…especially near the coast where the column is already saturating. Do not think any location will see more than .25 of an inch.
 
With thick clouds and drizzle/light rain temperatures will warm very little and many locations will not make 50.
 
Forecast models show the main area of light rainfall and lift shifting eastward tonight while the next short wave rotates through the western side of the trough over the SW US and prepares to move into TX Thursday night. Expect the dry layer to deepen some over SE TX on Thursday and this will shut down rainfall chances, but keep clouds in place. Increasing lift spreads from N MX into SW/W TX Thursday night with precipitation developing. Once again moisture will be limited, but more importantly the air column will be near or slightly below freezing west of a line from Waco to Del Rio suggesting light rain mixed with or changing to snow. Some significant snowfall will be possible over the Big Bend of TX into the Hill County region Thursday night and Friday morning. Think the snow may reach as far east as I-35 north of Austin into the Waco area. Locally, profiles are too warm for snow and moisture is very limited until later on Friday. Would not rule out a snow flurry or two over our western counties if they can penetrate that mid level dry layer.

Rain chances increase slightly Friday night and Saturday as the above mentioned short wave moves across TX. Main lift is aimed at N TX, but the combination of increasing isentropic lift over the surface cold dome will support at least a 30-40% chance of showers….best period for rainfall seems to be Saturday morning, but I am concerned that dry low levels from a re-enforcing shot of cold air on Thursday may have to be overcome before rainfall will reach the ground.
 
Cloudy and at time periods of rainfall will keep temperatures nearly uniform throughout the entire period with lows in the 40’s (maybe the upper 30’s) and highs in the lower 50’s.
 
May begin to see more warmer weather under sunnier conditions by early next week. 

[Srain]

Another Update from Jeff:

 

A few reports of light sleet mixed with light rain over the area in the past 30 minutes.
 
It appears that the mid levels are saturating enough to allow precipitation to reach the ground mainly in the form of light rain…however onset of light rain has been mixed with light sleet across Harris County. Surface temperatures have cooled into the upper 30’s and low 40’s, but this is still well above freezing. Even with evaporative cooling due to the precipitation process cooling the air temperature toward the dewpoint, the dewpoints are mainly at or above freezing.
 
May continue to see light sleet mix with the light rain for the next few hours especially at the onset of any precipitation, but all areas should transition over to pure rain by noon as the dry layer aloft shrinks and any evaporative processes end. With surface temperatures above freezing there will be no accumulations.

[Ed Lizard]

Looks like Permian Basin might get luckly confluence of precip and cold air.  Maybe with a little help from upsloping, MAF is pretty flat but almost a kilometer above sea level.  Further East, amounts lighter per GFS and Northeasterly flow not prime direction for cold low level temps.

[wxmx]

I agree that MRF could be the sweet spot with this...I would go with Presidio according to precip consensus from several models, but it's in a quite low spot being in the Rio Bravo/Grande valley, so surface temps might be marginal at times. I have visited the area quite a few times, my grandparents lived in Ojinaga/Presidio for many years.

[Srain]

Getting a bit more sleet than light rain at this time in NW Harris County.

[wxmx]

SAT could see some snow flakes fly by in a couple of days.

[wxmx]

As always, at least for my area, the CMC is too cold and wet, NAM is cold and dry, Euro is wet but warmer and GFS is dry and warm (as always is). One day (but not the 4th, I'm 99% certain), the canadian will be the right one.

 

 

[wxmx]

Signs are growing stronger for a McFarland signature (strong EPO ridge, PV near the Hudson bay, deep trough near the central CONUS) in the mid range (days 12-20). It's an uncommon event, so caution should be noted.

[Srain]

Signs are growing stronger for a McFarland signature (strong EPO ridge, PV near the Hudson bay, deep trough near the central CONUS) in the mid range (days 12-20). It's an uncommon event, so caution should be noted.

 

I was wondering when you would start noticing the longer range guidance. I tend to agree that once we get past this brief warm up next week, changes are looking more likely for those of us in the Central/Western areas. I friends back East may have to wait a bit longer before the never ending winter cancel calls ..   We folks across the West and the Plains certainly benefited from the pattern change back on December 12th.

[Ed Lizard]

I will content myself for the time being on hints from the Euro & GFS that Wednesday could be an active fun-derstorm day in Texas.

 

 

Don't want no stinking McFarland, that kills even somewhat cold tolerant vegetation even in the RGV.  A true cross-polar outbreak would kill all my citrus and might threaten my palms.

[Quixotic1]

A McFarland signature would be awesome.  December 83 and December 89 come to mind.  Jan/Feb of 96 too.  Not going to start wrapping pipes yet.  

[ams30721us]

Any sleet reports still from SE TX this afternoon?

[DFWWeather]

A McFarland signature would be awesome.  December 83 and December 89 come to mind.  Jan/Feb of 96 too.  Not going to start wrapping pipes yet.  

 

Let's add Feburay 1899 (the mother of all Arctic outbreaks), January 1930, late January/early February 1949, January 1962, January 1985, February 1989, December 1990, as being some of the most notable examples of McFarland Signatures (there are many others such as January 1911, 1912 (bitterly cold at DFW), and 1943). I'm not overly impressed (right now) with a McFarland signature yet during this time frame. Long-range ECMWF was onboard for awhile Christmas week, but has since backed off considerably. Latest runs, much like the current 12z GFS keep the core of cold in Canada near Hudson Bay with extending troughing back to the southwest, not too different form current pattern, with maybe H85 temps below -5°C at DFW. Not a strong Arctic outbreak at all more of a bleeding Arctic high (not McFarland). Most McFarland's produce H85 temps at DFW approaching -15°C at least. Not sure there will be enough Arctic air to tap into either by this time, as there was back in December.

 

Local NWS at DFW seems concerned about potential for accumulating snowfall again on Friday, but I think it will be well south of the Metroplex (if it occurs).

[Ed Lizard]

A McFarland signature would be awesome.  December 83 and December 89 come to mind.  Jan/Feb of 96 too.  Not going to start wrapping pipes yet.  

 

Someone obviously doesn't have citrus and palms in their yard...

[Quixotic1]

Let's add Feburay 1899 (the mother of all Arctic outbreaks), January 1930, late January/early February 1949, January 1962, January 1985, February 1989, December 1990, as being the most notable examples of McFarland Signatures. I'm not overly impressed with a major McFarland signature yet during this time frame. Long-range ECMWF was onboard for awhile Christmas week, but has since backed off considerably. Latest runs, much like the current 12z GFS keep the core of cold in Canada near Hudson Bay with extending troughing back to the southwest, not too different form current pattern, with maybe H85 temps below -5°C at DFW. Not a strong Arctic outbreak at all. Most McFarland's produce H85 temps at DFW approaching -15°C at least. Not sure there will be enough Arctic air to tap into either by this time, as there was back in December.

 

Local NWS at DFW seems concerned about potential for accumulating snowfall again on Friday, but I think it will be well south of the Metroplex (if it occurs).

Skepticism should abound but there's hope since most of the GFS Ensembles individual members show cold in some form or fashion (though the timing and severity differ).  Cross polar flow would probably be necessary to get a real stiff outbreak.  Then again, if it's not too severe, at least it won't crush any precip chances.  

 

Local NWS was excited Saturday about precip today. 

 

Someone obviously doesn't have citrus and palms in their yard...

Was in Houston in early March 2002 when a Blue Norther went through.  Never saw so many Hefty bags on plants in my life. 

[Srain]

I lived in Houston in 1962 and we certainly do not want a repeat of that Arctic Outbreak down here. It made the 1983/1989 events look rather paltry in comparison...  

[DFWWeather]

Local NWS was excited Saturday about precip today. 

 

I was too cause it looked very good on the models. Pattern not too different from February 2003, but that sure fell apart quick.