Daily Archives
March 4, 2015

…. WINTER STORM WARNINGS EFFECTIVE AT MIDNIGHT TONIGHT ….

by troyk | on Mar 04, 2015 | Comments Off

…. Authority / NWS Austin-San Antonio ….

INCLUDES THE COUNTIES OF...LLANO-BURNET-WILLIAMSON-VAL VERDE-
EDWARDS-REAL-KERR-BANDERA-GILLESPIE-KENDALL-BLANCO-HAYS-TRAVIS-

INCLUDING THE CITIES OF...LLANO...BURNET...GEORGETOWN...DEL RIO...
ROCKSPRINGS...LEAKEY...KERRVILLE...BANDERA...FREDERICKSBURG...
BOERNE...BLANCO...SAN MARCOS...AUSTIN

1032 AM CST WED MAR 4 2015

...WINTER STORM WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO NOON
CST THURSDAY...

THE NATIONAL WEATHER SERVICE IN AUSTIN/SAN ANTONIO HAS ISSUED A
WINTER STORM WARNING FOR FREEZING RAIN AND SLEET...WHICH IS IN
EFFECT FROM MIDNIGHT TONIGHT TO NOON CST THURSDAY.

* TIMING...ARCTIC AIR WILL POUR INTO THE AREA AFTER 6
  PM...FREEZING RAIN AND SLEET SHOULD BEGIN AROUND MIDNIGHT AND
  CONTINUE THROUGH NOON THURSDAY. TEMPERATURES SHOULD RISE ABOVE
  FREEZING AFTER NOON THURSDAY.

* MAIN IMPACT...FREEZING RAIN AND SLEET CAUSING ICING OF 1/10 INCH
  AND POSSIBLY A LITTLE HIGHER. THIS WILL MAKE FOR ICY ROADS AND
  HAZARDOUS DRIVING CONDITIONS.

* OTHER IMPACTS...SIDEWALKS...DECKS...AND OTHER SURFACES MAY BE
  DIFFICULT TO WALK ON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING MEANS ACCUMULATIONS OF SNOW...SLEET...
FREEZING RAIN OR FREEZING DRIZZLE ARE EXPECTED OR OCCURRING. THIS
WILL CAUSE CONSIDERABLE TRAVEL PROBLEMS AND MAY POSE A THREAT TO
LIFE AND PROPERTY.

TK’s Audio Weather Webcast (1010am CT – Wed/04Mar2015)

by troyk | on Mar 04, 2015 | Comments Off

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TK’s Austin and South Central Texas Weather Forecast….

by troyk | on Mar 04, 2015 | Comments Off

Updated 845am CT.. Wednesday / 04 March 2015

TODAY…. Cloudy with numerous rain showers and a few thunderstorms as an arctic cold front passes in the early and mid afternoon hours. Rainfall, where it occurs, given a 70% chance of rain at any given location, will average 1/4 to 1/2 inch. Turning windy and much colder with highs in the 60s in the afternoon just prior to frontal passage with temperatures falling through the 40s in the mid and late afternoon to near 40 by the evening rush hour. Southerly wind shifting northerly 15 to 25 mph with higher gusts as the front passes.

TONIGHT…. Cloudy and windy with numerous patches of rain through the mid and late evening hours then becoming mixed with or turning to freezing rain and sleet after midnight and continuing through the overnight hours resulting in potential hazardous driving conditions especially in areas north of Austin. Rainfall, where it occurs, given a 70% chance of precipitation at any given location, will average less than 1/4 inch. Ice accumulations of up to 1/10th inch. Low 30. Northerly wind 18 to 28 mph with some higher gusts.

THURSDAY…. Mostly cloudy with scattered patches of rain.. freezing rain.. and sleet before 12 noon.. a few snowflakes are possible. Decreasing clouds by mid and late afternoon. Possible hazardous driving conditions.. especially north of Austin.. in the morning. Rainfall, where it occurs, given a 30% chance of precipitation at any given location, will average only a few hundredths of an inch. Total ice accumulations.. where it occurs.. 1/10th inch or less. Little or no snow/sleet accumulation. High 38. North northeasterly wind 10 to 20 mph.

THURSDAY NIGHT…. Partly cloudy. Low 27. Northeasterly wind 5 to 10 mph.

FRIDAY…. Partly cloudy. High 44. Northeasterly wind 5 to 10 mph.

FRIDAY NIGHT…. Increasing clouds becoming mostly cloudy. Low 34. Light east northeasterly wind.

SATURDAY…. Mostly cloudy and a little warmer with a few sprinkles. Rainfall, where it occurs, given a 20% chance of precipitation at any given location, will average trace amounts. High 48. Light easterly wind.

SATURDAY NIGHT…. Mostly cloudy with a few sprinkles. Rainfall, where it occurs, given a 20% chance of precipitation at any given location, will average trace amounts. Low 39. Light wind.

SUNDAY…. Partly to mostly cloudy. High 57. Light southeasterly wind.

SUNDAY NIGHT…. Partly cloudy. Low 44. South southeasterly wind 5 to 10 mph.

MONDAY…. Partly cloudy. High 60. Southerly wind 5 to 12 mph.

MONDAY NIGHT…. Partly cloudy. Low 46. South southeasterly wind 5 to 10 mph.

TUESDAY…. Partly cloudy. High 64. Southerly wind 5 to 12 mph.

NATIONAL WEATHER SERVICE / 8 TO 14 DAY OUTLOOK
Valid Wednesday / 11 March 2015 through Tuesday / 17 March 2015…
Temperature… Near Average
Precipitation… Near Average

AUSTIN SUNSET/SUNRISE TIMES…..
Sunrise this morning (04 March)………………………………………….. 6:53 am
Sunset this evening (04 March)……………………………………………. 6:32 pm
Sunrise Thursday (05 March)………………………………………………. 6:52 am
Sunset Thursday (05 March)……………………………………………….. 6:33 pm

…. Time Change Coming Up ….
Central Standard Time (CST) back to Central Daylight Time (CDT)
at 2am on Sunday, 8 March 2015 when you should turn clocks
up one hour to 3am (“spring forward”). We lose an hour that we’ll
gain back at 2am on Sunday, 1 November 2015 when we move
back our clocks again as we go back to central standard time (CST).

TK’s Weather Discussion….

by troyk | on Mar 04, 2015 | Comments Off

Updated 915am CT – Wednesday / 04 March 2015

… Here Comes the Arctic Cold Front …
… Computer Models Trend A Little Warmer Temperature Wise …
… Possible Round of Wintry Precipitation Tonight into Thursday …

On this Wednesday morning…. a strong arctic cold front extends southwestward from western Arkansas and extreme southeastern Oklahoma into northern areas of central Texas then westward into west Texas and New Mexico. Temperatures, behind the front, have into the 20s and 30s over the Texas panhandle and Oklahoma. As a result of this surface weather pattern, our local surface winds are light and variable or light southeasterly.

In the upper levels of the atmosphere.. a deep upper level trough.. or line of low pressure southwestward from the western Great Lakes Across the central and southern Rockies and into southern Arizona and northwestern Mexico. As a result, our upper air winds at about 18,500 feet are southwesterly at 55 to 65 mph.

Dense fog and light drizzle and light rain continues over our area this morning as a south southeasterly surface wind flow tries to reestablish in advance of the arctic cold front to our north. Clouds are likely to linger along with good chances of rain showers and thunderstorms, with an attendant lightning risk, as the front approaches and then moves through the area early to mid afternoon.

With the passage of the arctic cold front, there will be a rapid drop in temperatures with temperatures in the 60s falling quickly through the 40s into the evening rush hour today. The latest numerical computer guidance suggests temperatures overnight tonight into early tomorrow /Thursday/ will not be as cold as I had earlier predicted with lows overnight closer to 30 to 31 degrees. In other words, once again, we find ourselves in the difficult forecast situation being that we will be sitting on the freezing line locally which will define exact precipitation types. In any case, an overrunning pattern will persist on top of the advancing shallow layer of arctic air with light precipitation likely later this afternoon through tonight with precipitation tapering off a bit during the morning and midday hours tomorrow. It is likely, given the very latest forecast guidance, that parts of our south central Texas area could see either a wintry mix or a changeover to freezing/frozen wintry precipitation tonight into midday Thursday with possible ice accumulations and associated hazardous driving conditions in some areas. All local interests should stay in close touch with the latest weather information from the National Weather Service through tomorrow.

It appears that the overrunning pattern, even with some breaks in the clouds late Thursday into Thursday night and Friday, will linger late week into the weekend as temperatures only slowly warm just as we saw this past weekend.

Regarding my forecast, my local forecast confidence: My forecast confidence is lowered to medium today through tomorrow (as it relates to the extent and intensity of freezing temperatures and associated precipitation types) then back up to high tomorrow night through Friday and the weekend as it regards the basic weather pattern and precipitation occurrence, timing and amounts. Although it is a little lower than yesterday, I continue to have low to medium confidence of some type of freezing/frozen precipitation tonight into tomorrow.

Have a good Wednesday….
Meteorologist Troy Kimmel

Contact me:
tkimmel@austin.utexas.edu

http://www.facebook.com/troykimmel

… WINTER WEATHER EVENT TONIGHT/EARLY THURSDAY …

by troyk | on Mar 04, 2015 | Comments Off

Austin / Travis County and South Central Texas Weather Statement #3
Prepared by UT University/Incident Meteorologist Troy Kimmel
830am CT – Wednesday / 04 March 2015

…. Potential Winter Weather Event Tonight into Thursday Morning ….
…. Computer Models Trend Not Quite So Cold Tonight ….

NWS WATCHES / ADVISORIES / WARNINGS:
None at this time

SYNOPTIC/FORECAST REASONING:
Ahead of the arctic cold front.. that currently extends from southeastern Oklahoma
into north central Texas to the Waco area to north of San Angelo.. we’re seeing
dense fog and light rain with temperatures in the upper 50s to near 60 degrees. The
arctic cold front will pass south southeastward through the Austin and south central
Texas area during the early to mid afternoon hours.

A couple of things I’m seeing this morning… (1) the coldest air is lagging behind the
front with the 20s and 30s hanging back over Oklahoma – this air isn’t as cold as I
thought it would be over Oklahoma this morning. (2) Computer models over the last
24 hours have trended  warmer locally tonight into  Thursday morning. In short, I’m
not as certain today of the temperatures being as cold as I’ve been advertising for
late tonight into early Thursday morning. That being said, please keep in mind that our
numerical forecast models have a tendency to be too slow with arctic frontal passages
and tend to underestimate the intensity of cold air in these type situations.. so we need
to continue to watch the situation.

I still expect to see the 50s and lower 60 degree temperatures today fall quickly
with the advancement of the cold front this afternoon. I now expect to temperatures
to fall through the 40s as we go into the afternoon/evening rush hour. Overnight, we’ll
see temperatures fall to closer to 30 degrees by daybreak Thursday.

As the relatively shallow arctic cold air slides southward over the area, several
upper air low pressure disturbances will move across the area tonight into Thursday.
This will produce an overrunning clouds and light precipitation which will
likely persist through Thursday. A mixed rain.. freezing/frozen winter precipitation
will likely occur over parts of south central Texas based on the latest guidance. Based
on what I’m seeing this morning, I’m thinking that we.. once again.. could find ourselves
not quite as cold and more on the border of the freezing temps and the areas where
potential ice could have an effect.

While we will likely see some breaks in the clouds by Thursday night into Friday, the
cloudy overrunning pattern is likely to kick back in by Friday night into the weekend
with temperatures only slowly warming.

All local interests across the area should stay in close touch with the latest south central
Texas forecast and weather information from the National Weather Service.

THREAT(S) FOR AUSTIN METRO AND IH35 CORRIDOR COUNTIES:
Low to moderate probability for a wintry precipitation mix (rain, freezing rain, sleet, snow)
Geographic area: IH35 Corridor Counties / Williamson, Travis, Hays
Time Period: 4pm Wednesday through 12 noon Thursday
Ice Accumulation: Possible with potential hazardous driving conditions 7pm Wed-1 pm Thu
Snow Accumulation: Little or none

MY FORECAST CONFIDENCE:
Weather system evolution: High to Very High
Precipitation chances: High Wednesday afternoon.. Wednesday night into early Thursday
Liquid precipitation (rain) chances: High Wednesday afternoon.. Wednesday night into early Thursday
Freezing precipitation (freezing rain/freezing drizzle) chances: Low to Moderate
Frozen precipitation (snow/ice pellets-sleet) chances: Low to Moderate
Thunderstorm/lightning chances: Moderate to high Wednesday to 4 pm
Severe thunderstorm chances: None

CALL TO ACTION:

Please remain “weather aware” and listen for the latest weather statements,
advisories, watches and warnings from the National Weather Service.

Make sure that your NOAA All Hazards Weather Radio is operational and are
set to alarm in case of severe and inclement weather watches and/or warnings.

FOLLOWUP STATEMENTS:

I will continue to keep you informed regarding this severe/inclement weather
event. Any questions, please let me know at tkimmel@austin.utexas.edu

tk