NOVEMBER: Warming Up To End The Month

[unome]

Latest Storm Summary (updated 1416Z 11/24/2013)

all of it here: http://www.wpc.ncep.noaa.gov/discussions/nfdscc1.html

parts of it:

STORM SUMMARY NUMBER 06 FOR SOUTHWEST U.S. TO SOUTHERN PLAINS
WINTER STORM
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
900 AM CST SUN NOV 24 2013

AT 800 AM CST...THE SURFACE LOW PRESSURE HAS DISSIPATED ALONG WITH
THE SURFACE FRONT. AN UPPER LEVEL VORTEX REMAINED ANCHORED OVER
THE SOUTHWEST AND WAS TRIGGERING PRECIPITATION AHEAD OF IT FROM
ARIZONA TO TEXAS.

TO THE EAST... SOME LIGHT TO MODERATE SNOW
WAS FALLING ACROSS THE ENTIRE STATE OF NEW MEXICO.. THE TEXAS
PANHANDLE... AND WESTERN OKLAHOMA... WITH SLEET AND FREEZING RAIN
FARTHER SOUTH IN CENTRAL TEXAS. THERE IS ALSO RAIN FALLING ACROSS
SOUTH CENTRAL TEXAS.

...SELECTED STORM TOTAL SNOWFALL IN INCHES FROM 500 AM CST THU NOV
21 THROUGH 800 AM CST SUN NOV 24...

...TEXAS...
DIMMIT 8.0
FRIONA 8.0
MEMPHIS 7.0
TULIA 7.0
FARWELL 6.0
LAKEVIEW 5.0
STRATFORD 5.0
WHITE DEER 5.0
LOCKNEY 1 S 4.6
CANYON 1 NNW 4.0
HAPPY 4.0
AMARILLO 7 ENE 3.7

...SELECTED STORM TOTAL FREEZING RAIN ICE AMOUNTS IN INCHES FROM
500 AM CST THU NOV 21 THROUGH 800 AM CST SUN NOV 24...

...TEXAS...
CROSBYTON 0.25
INGRAM 14 NW 0.25
MOUNTAIN HOME 2 NNE 0.25
TAHOKA 0.25
ALEDO 0.10
RENO 0.10
WEATHERFORD 0.10



...SELECTED STORM TOTAL SLEET IN INCHES FROM 500 AM CST THU NOV 21
THROUGH 800 AM CST SUN NOV 24...

...TEXAS...
JAYTON 1.00
BRYSON 0.10
GRAHAM 0.01

THE RAIN AND SNOW ACROSS THE SOUTHWEST IS EXPECTED TO CONTINUE
DIMINISHING ACROSS THE REGION ON SUNDAY.

UP TO 2
INCHES OF SNOW ACROSS NORTHERN TEXAS AND CENTRAL OKLAHOMA IS
POSSIBLE ON SUNDAY ALSO. OVER HALF AN INCH OF ACCUMULATING ICE
FROM FREEZING RAIN WILL BE POSSIBLE IN CENTAL TEXAS...AND WILL
COME TO AN END BY MONDAY EVENING.

THE NEXT STORM SUMMARY WILL BE ISSUED BY THE WEATHER PREDICTION
CENTER AT 300 PM CST. PLEASE REFER TO YOUR LOCAL NATIONAL WEATHER
SERVICE OFFICE FOR ADDITIONAL INFORMATION ON THIS EVENT.

[srainhoutx]

Looking at the big picture water vapor imagery as well as radar and surface obs, we can see the U/L moving E as a strong short wave drops S into the Northern Rockies/Northern Plains and heads SE.



There is also a strong disturbance riding ENE across Mexico from the Pacific where abundant moisture is streaming inland. I suspect the U/L will move into New Mexico and turn SE and cross Texas over the Hill Country before merging with a developing Coastal Low that current surface analysis depicts as a Coastal trough near Corpus Christi. After many years of watching Winter Weather events across Texas dating back to my memories in the mid 60’s going forward, any cold core upper low/trough crossing the State tends to be a forecasting nightmare and many a bust has happened, both as not being forecasted correct or too conservative as well as going overboard and nothing happening. It is time to focus on what is happening ‘real time’ and report those observations. Stay safe and let’s hope we do not see a widespread ice storm that would be a real mess from a societal standpoint.

[srainhoutx]

A lot of reports now coming in across the NWS San Angelo forecast area of freezing rain up to .25 inches accumulating on elevated surfaces.

[srainhoutx]

Morning Update from Jeff:

Winter storm unfolding over TX this morning.

Secondary surge of dry and cold arctic air has moved into SE TX overnight from the NE resulting in a gradual decrease in clouds roughly along and NE of a line from Huntsville to High Island. This surge has also resulted in dewpoints falling into the 20’s for most of the area and the formation of a very dry layer in the 900 to 700mb level as noted on the 12Z FWD, SHV, and LCH soundings. In the mid levels moisture continues to overrun the cold dome at the surface as shown on the CRP sounding (no dry layer). The tail end of a lead short wave ahead of the main large scale upper level storm over AZ currently is moving across C and N TX with rain mixed with sleet at times. Expect this feature to progress ENE today with clouds thickening and lower with time over SE TX and possibly some light rain/sleet mix over our W/NW counties this afternoon.

Tonight-Monday Evening:

SE TX:

Upper level storm will move into NM forcing surface low pressure formation along the lower TX coast. Good moisture advection will occur above the surface cold dome tonight with light rain and drizzle developing from SW to NE across the region by Monday morning. Initial wet bulbing (aka evaporative cooling) from the precipitation falling through the very dry low level air will help cool the air column some, but not enough to result in a full change over to sleet and not enough to bring surface temperatures to freezing. Expect to see some sleet report this afternoon and tonight across the region mixed with the rainfall, but there will be no accumulation as surface temperatures remain in the mid to upper 30’s. It will take some time for the falling precipitation to moisten the low levels and this may prevent much in the way of rainfall for much of the night.

Warm aid advection above the surface cold dome increasing on Monday and expect widespread rainfall to develop. Short term models continue to suggest banded moderate to at times heavy rainfall advancing inland from the coast by late Monday as the surface low crosses our coastal waters. Think the heaviest rains will be along and S of US 59 and then another band likely across our NW counties where lift is maximized from the upper level system. Rainfall amounts will average 1-2 inches across much of the area.

Tides will also be increasing as winds veer to the ENE on the north side of the developing surface low off the lower TX coast. ENE winds are a favorable wind direction for elevated tides along the upper TX coast and tides could run .5 to 1.5 feet above normal by late Monday.

Along and W of I-35:

Bigger concerns will be found within the Winter Storm Warning area from roughly Del Rio to W of Austin to Dallas. Here the surface temperatures will be at or below freezing and various forecasted profiles indicate a prolonged mix of freezing rain and sleet. Could see some hefty accumulations of .25 to .75 of an inch of ice in the warning area along with sleet accumulation. Travel will be extremely hazardous in these areas by late this afternoon. Currently a tough call around Austin as this area will be right on the dividing line and it is somewhat questionable if surface temperatures will fall to freezing. Could see some minor icing in this area, but not to the extent of area just to the NW.

Monday night-Tuesday night:

Surface low progresses into LA, but upper level storm system will still be moving across the state. While the best moisture is carried eastward with the surface low, there does appear to be just enough moisture left when combined with the strong lift from the upper level low to produce additional precipitation into Tuesday. Of some concern is the cooling of the air column as the cold pocket associated with the upper level storm system moves overhead. Forecast soundings still look fairly marginal for sleet/snow production over SE TX, but the dynamics associated with these systems can sometimes compensate for a lack of moisture and meager temperature profiles. For now will keep everything liquid over the area, but this time period will need further evaluation in the next 24 hours.

Tuesday night-Friday:

Winter storm exits TX with cold and dry NW flow in place. Skies should gradually clear on Wednesday setting the area up for freezing conditions on Thursday morning. Slow but gradual warming trend begins on Friday with temperatures finally breaking 60.

[SusieinLP]

Sun peeking out through clouds here in La Porte.. Still quite breezy.

[srainhoutx]

Looking for snow? Ski Taos live webcam image...

[srainhoutx]

11242013 11AM EWX image_full1.gif

[unome]

WPC's 3 pm storm summary: http://www.wpc.ncep.noaa.gov/discussions/nfdscc1.html

just a snippet, read all at the link

UP TO A QUARTER INCH OF ACCUMULATING ICE FROM FREEZING RAIN WILL
BE POSSIBLE IN CENTRAL TEXAS...

THE NEXT STORM SUMMARY WILL BE ISSUED BY THE WEATHER PREDICTION
CENTER AT 900 PM CST. PLEASE REFER TO YOUR LOCAL NATIONAL WEATHER
SERVICE OFFICE FOR ADDITIONAL INFORMATION ON THIS EVENT.


cool link from srh to quickly see graphicasts from all southern region offices

http://innovation.srh.noaa.gov/ROC/gcastgis/

[skidog40]

I turned it on

[Portastorm]

unome, thanks for the link! That's pretty cool stuff.

[tireman4]

From HGX AFD...


000
FXUS64 KHGX 242117
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
317 PM CST SUN NOV 24 2013

.DISCUSSION...
A WEAK S/WV MOVING ACROSS THE CWA WAS BRINGING A SWATH OF LIGHT
RAIN ACROSS THE REGION THIS AFTN. THERE SHOULD BE A BREAK IN THE
PRECIP THIS EVENING IN THE WAKE OF THE S/WV. AN UPPER LEVEL LOW
WILL OVER THE 4 CORNERS WILL MOVE EAST LATE TONIGHT INTO MONDAY
AND APPROACH THE TEXAS PANHANDLE. THE SYSTEM WILL THEN MOVE S-SE
TOWARD SOUTH CENTRAL TEXAS. LIFT ON THE EAST SIDE OF THIS SYSTEM
WILL INCREASE AS THE UPPER LOW APPROACHES. A SERIES OF WEAK UPPER
LEVEL DISTURBANCES WILL MOVE ACROSS THE AREA IN THE SW FLOW ALOFT.
UPPER LEVEL DIVERGENCE WILL ALSO INCREASE AS THE UPPER LEVEL LOW
NEARS. FCST SOUNDINGS SHOW SATURATION BEGINNING IN EARNEST BETWEEN
09-12Z MON MORNING. THE SUB CLOUD LAYER WILL INITIALLY BE VERY DRY
AND AS THE PRECIPITATION BEGINS TO FALL...SFC TEMPS WILL FALL TO
BETWEEN 32-36 DEGREES NORTH AND 34 TO 40 DEGREES SOUTH. THERE IS A
SMALL WINDOW...MAINLY BETWEEN 4 AM AND 10 AM WHERE SOME THE PRECIP
NORTH OF A CALDWELL TO TRINITY LINE...COULD BRIEFLY TRANSITION TO
FREEZING RAIN OR BECOME MIXED WITH SLEET. ELEVATED BRIDGES WILL
ALSO BE A FEW DEGREES COLDER THAN SURROUNDING SURFACE ROADS AND
WILLO NEED TO BE WATCHED FOR ICY SPOTS. BY 16Z...FEEL AIR MASS
WILL HAVE WARMED ENOUGH THAT PRECIP AREAWIDE WILL BE RAIN. MONDAY
LOOKS TO BE COLD AS TEMPS STRUGGLE TO REACH THE LOWER 40S. FCST
SOUNDINGS LOOK SUPER SATURATED AND PERIODS OF RAIN...AT TIMES
HEAVY...WILL PERSIST THROUGH ABOUT 06Z TUESDAY. RAINFALL TOTALS
WILL AVERAGE 1 TO 2 INCHES AREAWIDE WITH SOME ISOLATED 3 TO 4
INCH TOTALS.

THE UPPER LOW WILL DIG FURTHER SOUTH ON TUESDAY AND THIS WILL
ALLOW JET DYNAMICS TO FOSTER ADDITIONAL RAIN. PREFER THE ECMWF
WITH THE POSITION OF THE UPPER LOW AND STRONGER UPPER LEVEL
DIVERGENCE/JET DYNAMICS. THE UPPER LEVEL TROUGH WILL BE EAST OF
THE REGION BY 06Z WEDNESDAY. ALL PRECIP WILL END QUICKLY LATE
TUESDAY AFTN AS SUBSIDENCE IN THE WAKE OF THE TROUGH DEVELOPS.
SKIES WILL CLEAR QUICKLY TUES NIGHT AND LOW TEMPS WILL APPROACH
FREEZING BY WED MORNING. A LIGHT FREEZE WILL BE POSSIBLE NORTH OF
A COLUMBUS TO TOMBALL TO CLEVELAND LINE. CLEAR SKIES AND
UNSEASONABLY COLD TEMPS WILL PREVAIL THROUGH FRIDAY. CLEAR
SKIES...LIGHT WINDS AND DRY AIR WILL ALLOW FOR VERY COLD TEMPS ON
THANKSGIVING MORNING. A HARD FREEZE WILL BE POSSIBLE OVER THE
EXTREME NORTH AND A LIGHT FREEZE POSSIBLE OVER THE REMAINDER OF SE
TX. 43

&&

.MARINE...
LITTLE CHANGE IN THE POSITIONING OF LARGE U.S. UPPER MIDWEST HIGH
PRESSURE AND LOWER SOUTHERN GULF PRESSURE...WITH A HEALTHILY DOSE OF
COOLER AIR OVERRUNNING LOW TO MID 60 DEGREE WATER...WILL KEEP STRONG
NORTHERLIES IN PLACE THROUGH MID-WEEK. CHURNED UP SEAS WILL REMAIN
AT CAUTION/ADVISORY LEVELS OVER THE NEXT COUPLE OF DAYS. THE EARLY
WORK WEEK DEVELOPMENT AND EVENTUAL EASTERN PROGRESSION OF A WESTERN
GULF SURFACE LOW WILL AGAIN TIGHTEN THE LOCAL GRADIENT ALONG ITS
BACKSIDE. A COLD FRONTAL PASSAGE TUESDAY WILL STRENGTHEN OFFSHORE
FLOW EVEN MORE...LIKELY MAINTAINING/RE-HOISTING ADVISORY FLAGS FOR
BOTH WINDS AND SEAS. THE APPROACH AND PASSAGE OF AN UPPER LOW
TUESDAY HAS HIGH-END PRECIPITATION CHANCES OF PRIMARILY RAIN IN THE
CURRENT MARINE FORECAST. 31




http://forecast.weather.gov/product.php ... glossary=1

[srainhoutx]

Interestingly my temp in NW Harris County is the same as Austin at 38F.. Nasty cold and rainy day. Now we will see if the upper low has enough dynamics and moisture to bring messy weather tomorrow morning before all this dreary weather moves E for Thanksgiving. We could see a rather widespread freeze early Thanksgiving morning before the warm up begins.

[srainhoutx]

EWX reports 0.06 freezing rain covering trees and railings in Boerne.

[srainhoutx]

Morning Update from Jeff:

Winter Storm in progress over TX this morning with ice/snow across much of western TX extending into the Hill Country and eastward to just west of Fort Worth.

Locally widespread rainfall has developed as expected over the region with amounts thus far in the .25 to .75 of an inch range across the area. Temperatures have cooled into the upper 30’s and lower 40’s with the onset of the rainfall and evaporative cooling, but this process has now ended and the low level thermal profile is now isothermal. Expect temperatures to hold around 40 degrees the entire day and into tonight. Soundings this morning at both LCH and CRP show the freezing level way up at around 12,000 ft with significant warming from the surface to about 800mb. This sounding supports nothing more than cold rain and there have been no sleet reports across SE TX this morning.

Today:

Upper level storm system over NM/NW TX will dive SE toward C TX and the middle TX coast by early Tuesday. This will drive the formation of a surface low off of Brownsville which is underway at this time. Bands of rainfall will continue to develop as warm moist Gulf air is forced up and over the cold arctic dome at the surface. 10C 850mb temperature line appears to match well with the model QPF of heavier rainfall amounts running near/just south of US 59. In fact the radar trends this morning appear to be lining up very well with short term model guidance from yesterday evening suggesting the heaviest rains near/just south of US 59. May see a brief break in the widespread rainfall this afternoon late before the onset of strong dynamical forcing tonight associated with the main upper level storm system.

Tonight-Tuesday Midday:

Strong upper level system drops SE in an unusual track across TX. Impressive 110kt mid level jet streak rounds the base of this feature after dark out of NE MX and carves across the coastal bend into SE TX. Expect strong forcing to generate more rainfall especially along the coast. Surface low off of Brownsville currently will track NE and across our southern coastal waters tonight with winds shifting from the NE to N and NW with time. This feature will help draw the highest moisture levels eastward which becomes very important by early Tuesday.

P-type:

Cold temperatures aloft begin to overspread the region tonight with the most notable cooling noted across our western and northern counties. This cooling is in response to the cold pocket associated with the core of the upper level low. HRRR forecast soundings for College Station at 600am Tuesday show nearly the entire column (except maybe the lowest 1,000ft) falling below freezing and saturated below 800mb with a large dry layer above that. As is usually the case in this area the “great” battle between the arriving cold air aloft and the amount of available moisture will determine if any frozen precipitation falls. Forecast soundings certainly show significant cooling of the air column between midnight and 600am north of a Columbus to Conroe to Livingston line, but at the same time moisture is rapidly being carried eastward away from the area. With that said, the position of the core of the upper level feature potentially just SW of the area between Houston and Matagorda Bay could result in some moisture being wrapped back NW around the northern side of the upper low and falling as snow.

It is fairly rare to have P-type rain to snow over SE TX with upper level lows as they usually track just north of the area over N TX. Usually the cold air is lagging the moisture and the rain shuts off prior to it being cold enough for snow. Of the 3 major snow events in the last decade (Dec 04, Dec 08, Dec 09) only the Dec 08 event shows some similarities to the potential for Tuesday morning and that event was pretty much a surprise and dropped upwards of 6 inches of snow in Liberty County.

For now think that most of the moisture will have been carried east of the area by the time the air column can support the changeover. With that said would not be surprised to see some light snow reports N and W of a line from Columbus to Conroe to Livingston early Tuesday. Will have to keep a close eye on this part of the forecast this afternoon and evening as the short range guidance can better resolve this period to determine if any greater amounts of moisture would be present which would increase the chances for snow. Even if snow does fall, the surface temperatures are expected to remain above freezing resulting in melting on contact with the ground.

Wednesday-Friday:

Winter storm moves east of the state with dry cold NW flow in control. Clearing skies on Wednesday will set the stage for what appears to be a fairly widespread freeze on Thanksgiving morning. Could see lows well below freezing over our northeast counties with many areas falling into the upper 20’s and lower 30’s. Some area have yet to freeze this fall so a freezing warning will likely be needed. High temperatures should finally break 50 on Thanksgiving day and may reach close to 60 on Friday.

Note: while it seems like a long time ago, the high temperature for Houston last Sunday was a toasty 85 degrees, the high yesterday a week later was 50.

[MontgomeryCoWx]

speak for yourself... I want a hard freeze. Deep freeze.

[srainhoutx]

If someone wants to start a December Topic, it appears we may have some 'interesting weather' the first couple of weeks of that month.

[srainhoutx]

FWD reported some light sleet in Ft Worth a bit ago. Radar did not show much in the way of returns.

[srainhoutx]

It looks like another round of heavier precip will arrive across the Houston Metro late in the evening rush hour period. Returns have increased as another upper air disturbance rides across Mexico from the Pacific and the Low Pressure out in the Gulf continue to bring over running conditions across the Southern half of Texas. The cold core upper low is dropping SSE now and should be over Central Texas during the overnight hours.

[srainhoutx]

Current departures at 19Z ~vs~ 1981-2010. Notice where ALL the major departures are located.

[srainhoutx]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
318 PM CST MON NOV 25 2013

.SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...
LIGHT TO MODERATE RAIN WILL CONTINUE THIS AFTERNOON MAINLY ACROSS
AREAS ALONG AND SOUTHEAST OF THE I-35 CORRIDOR AS AN UPPER LEVEL
LOW MOVES ACROSS THE STATE. OCCASIONAL LULLS IN THE ACTIVITY ARE
EXPECTED...BUT CHANCES FOR RAIN WILL CONTINUE OVERNIGHT ACROSS
MUCH OF THE REGION. DRIER AND COLDER AIR ENTERING THE REGION JUST
ABOVE THE SURFACE WILL RESULT IN THE POTENTIAL FOR SNOW FLURRIES
TO MIX-IN WITH THE COLD RAIN ACROSS THE EASTERN HILL COUNTRY AND
ADJACENT PORTIONS OF THE I-35 CORRIDOR. DUE TO LOW PROBABILITIES
OF OCCURRENCE AND NO ACCUMULATIONS...HAVE OPTED TO ADDRESS THE
SCENARIO WITH A SPECIAL WEATHER STATEMENT.