First Freeze Warning of the season for Austin metro area

November 12th, 2014 at 3:50 pm by under Weather

Tonight will be cold and breezy. Lows are expected to fall to the upper 20s north and upper 30s south. A Freeze warning will be in effect tonight beginning at 11PM for areas north of a line from Del Rio to San Antonio and along the I 35 corridor.
URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
313 PM CST WED NOV 12 2014

...FREEZING TEMPERATURES EXPECTED ACROSS THE HILL COUNTRY AND
WEST OF I-35 PORTIONS OF THE ESCARPMENT FROM 11 PM CST TONIGHT
THROUGH 10 AM CST THURSDAY MORNING...

.COLD HIGH PRESSURE WILL CONTINUE ACROSS THE HILL COUNTRY AND
SOUTH CENTRAL TEXAS THE NEXT FEW DAYS. TEMPERATURES WILL FALL TO
FREEZING BY MIDNIGHT IN SOME SPOTS...BECOME MORE WIDESPREAD
OVERNIGHT AND THEN RISE ABOVE FREEZING BY 10 AM. MANY AREAS OF THE
HILL COUNTRY THAT STAYED ABOVE FREEZING LAST NIGHT INTO THIS
MORNING WILL FALL BELOW FREEZING BY THURSDAY MORNING. THE FEW
SPOTS THAT STAYED ABOVE FREEZING IN GILLESPIE AND KERR COUNTIES
WILL FALL BELOW FREEZING BY THURSDAY MORNING. AREAS ALONG THE
ESCARPMENT WEST OF I-35 IN HAYS...TRAVIS AND WILLIAMSON COUNTIES
WILL HAVE FREEZING TEMPERATURES FOR 2 TO 3 HOURS AROUND SUNRISE
THURSDAY. HOWEVER...THE AUSTIN METRO AREA WILL REMAIN JUST ABOVE
FREEZING. A MORE WIDESPREAD FREEZE IS EXPECTED ACROSS SOUTH
CENTRAL TEXAS THURSDAY NIGHT INTO FRIDAY MORNING.

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
313 PM CST WED NOV 12 2014

...FREEZE WARNING IN EFFECT FROM 11 PM THIS EVENING TO 10 AM CST
THURSDAY...

THE NATIONAL WEATHER SERVICE IN AUSTIN/SAN ANTONIO HAS ISSUED A
FREEZE WARNING...WHICH IS IN EFFECT FROM 11 PM THIS EVENING TO
10 AM CST THURSDAY.

* TEMPERATURE...26 TO 32 DEGREES

* IMPACTS...THIS WILL BE THE FIRST FREEZE OF THE SEASON FOR MANY
  LOCATIONS. THESE TEMPERATURES MAY DAMAGE COLD SENSITIVE PLANTS.
  EXPOSED PIPES MAY FREEZE. OUTDOOR PETS MAY NEED EXTRA
  PROTECTION.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FREEZE WARNING MEANS SUB-FREEZING TEMPERATURES ARE IMMINENT OR
HIGHLY LIKELY. THESE CONDITIONS WILL KILL CROPS AND OTHER
SENSITIVE VEGETATION.

A widespread freeze is possible late Thursday night through Friday morning, with the exception of far southwest areas, near Eagle Pass. A hard freeze, with temperatures of 24-27 degrees, is possible across portions of the Hill Country.

Today is Winter Weather Awareness Day for Texas! Do you know what steps to take to be prepared for potential winter weather and it’s impacts?

Today Is Texas Winter Weather Awareness Day

November 12th, 2014 at 8:23 am by under Weather

noaassml

austin snow

We couldn’t have written the script better than Mother Nature did this year.  We woke up this morning to easily the coldest temperatures we have seen so far this season, and the chilly Arctic air isn’t going to leave us alone for at least another week or so.   Therefore we couldn’t have had this year’s “Texas Winter Weather Awareness Day” fall on a more appropriate date!!  Here are a few of the best Winter storms can strand motorists traveling northern routes in Texas, sometimes striking South Texas and coastal areas. When winter storms threaten, monitor broadcast media and NOAA Weather Radio for information. Keep your gas tank full to avoid ice in the tank and fuel lines. On icy roads, drive slowly and increase distance required for stopping. Watch for downed trees and power lines across roads. If power is out, treat all intersections as four-way stops.

Emergency Supplies For Vehicle

  • Blankets/sleeping bags and extra clothing, mittens and hat
  • Cell phone, radio, flashlight, extra batteries
  • First-aid kit and pocket knife
  • High calorie, non perishable food, bottled water
  • Sack of sand or cat litter for de-icing roadway
  • Windshield scraper, tool kit, booster cables, tow rope and shovel

Click here for the complete EMERGENCY SUPPLIES KIT CHECKLIST.  This is something you should have in your car, if you are taking a trip during a time that a winter strike is in the forecast.

 

i 35

 

Emergency Tips For Home

If heavy ice on power lines cuts utility service, be extremely careful using generators or gas powered equipment. Carbon monoxide (CO) is invisible, odorless and deadly. It can build up in a matter of minutes. Do not use generators, charcoal grills or gas grills inside the house, garage or enclosed space. Do not try to heat the house using a gas range or oven. Be prepared at home:

  • Battery-powered NOAA Weather Radio, batteries, flashlights, cell phone and chargers, manual can opener
  • One-week supply of food, water, medicine, medical supplies and items for special health care needs, babies and the elderly
  • Pet supplies, kitty litter or sand for de-icing steps and walkways
  • Heating fuel, properly ventilated emergency heating source such as a fireplace, wood stove or space heater
  • Fire extinguisher, smoke detector, carbon monoxide detector
  • Warm clothing and extra blankets

 

For additional winter weather preparedness information, click on:

 

 

KNOW THE TERMS

Know the terms used to describe changing winter weather conditions and what actions to take. These terms can be used to determine the timeline and severity of an approaching storm. (Advisory / Watch / Warning). The NWS also issues advisories and warnings for other winter weather, including blizzards, freezes, wind chill, lake effect snow, and dense fog. Be alert to weather reports and tune in for specific guidance when these conditions develop.

Freezing Rain - Rain that freezes when it hits the ground, creating a coating of ice on roads, walkways, trees and power lines.

icy car

Sleet - Rain that turns to ice pellets before reaching the ground. Sleet also causes moisture on roads to freeze and become slippery.

Wind Chill- Windchill is the temperature it “feels like” when you are outside. The NWS provides a Windchill Chart to show the difference between air temperature and the perceived temperature and the amount of time until frostbite occurs. For more information, visit: www.nws.noaa.gov/om/windchill.

Winter Weather Advisory - Winter weather conditions are expected to cause significant inconveniences and may be hazardous. When caution is used, these situations should not be life threatening. The NWS issues a winter weather advisory when conditions are expected to cause significant inconveniences that may be hazardous. If caution is used, these situations should not be life-threatening.

Winter Storm Watch - A winter storm is possible in your area. Tune in to NOAA Weather Radio, commercial radio, or television for more information. The NWS issues a winter storm watch when severe winter conditions, such as heavy snow and/or ice, may affect your area but the location and timing are still uncertain. A winter storm watch is issued 12 to 36 hours in advance of a potential severe storm. Tune in to NOAA Weather Radio, local radio, TV, or other news sources for more information. Monitor alerts, check your emergency supplies, and gather any items you may need if you lose power.

Winter Storm Warning - A winter storm is occurring or will soon occur in your area.

Blizzard Warning - Sustained winds or frequent gusts to 35 miles per hour or greater and considerable amounts of falling or blowing snow (reducing visibility to less than a quarter mile) are expected to prevail for a period of three hours or longer.

Frost/Freeze Warning - Below freezing temperatures are expected.

 


Freezing temperatures expected in Central Texas

November 11th, 2014 at 1:42 pm by under Weather
URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
321 PM CST TUE NOV 11 2014

FREEZING TEMPERATURES EXPECTED ACROSS MUCH OF THE HILL COUNTRY
FROM 3 AM CST TONIGHT THROUGH 9 AM CST WEDNESDAY MORNING

.IN THE WAKE OF A STRONG COLD FRONT...FREEZING TEMPERATURES CAN BE
EXPECTED ACROSS MUCH OF THE HILL COUNTRY LATE TONIGHT INTO
WEDNESDAY MORNING. IN ADDITION...WINDS OF 1O T0 15 MPH WILL MAKE
IT FEEL EVEN COLDER. 

LLANO-BURNET-EDWARDS-REAL-KERR-GILLESPIE-KENDALL-BLANCO-
INCLUDING THE CITIES OF...LLANO...BURNET...ROCKSPRINGS...LEAKEY...
KERRVILLE...FREDERICKSBURG...BOERNE...BLANCO
321 PM CST TUE NOV 11 2014

...FREEZE WARNING IN EFFECT FROM 3 AM TO 9 AM CST WEDNESDAY...

THE NATIONAL WEATHER SERVICE IN AUSTIN/SAN ANTONIO HAS ISSUED A
FREEZE WARNING...WHICH IS IN EFFECT FROM 3 AM TO 9 AM CST
WEDNESDAY. 

* TEMPERATURE...LOWS 29 TO 32.

* IMPACTS... THIS WILL BE THE FIRST FREEZE OF THE SEASON FOR MANY
  LOCATIONS. THESE TEMPERATURES MAY DAMAGE COLD SENSITIVE PLANTS.
  EXPOSED PIPES MAY FREEZE. OUTDOOR PETS MAY NEED EXTRA
  PROTECTION. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FREEZE WARNING MEANS SUB-FREEZING TEMPERATURES ARE IMMINENT OR
HIGHLY LIKELY. THESE CONDITIONS WILL KILL CROPS AND OTHER
SENSITIVE VEGETATION.

Freezing temperatures will be possible Thursday morning across the northern Hill Country. Mid 30s are forecast across the I-35 corridor, with upper 30s to lower 40s across southern areas.

A freeze is now forecast Friday morning across most of the Hill Country and I-35 corridor from New Braunfels to Georgetown. Models have been trending colder, and there is the potential this freeze line could be moved slightly farther south and east. Stay tuned.

A widespread freeze is likely tonight/Wednesday morning. Lows will be in the lower to upper 20s area-wide.

Freezing temperatures are expected overnight tonight and Wednesday morning along and north of a line from Lampasas to Hillsboro to Canton. A Freeze Warning has been issued for this area beginning at 2 AM Wednesday morning. Wednesday morning temperatures will fall into the upper 20s to 32 degrees in the Warning area. To the southeast of the Warning area, temperatures Wednesday morning will be in the low to mid 30s, but these areas may reach freezing Thursday or Friday morning. Breezy winds of 10-20 mph will occur Wednesday morning resulting in wind chill readings in the teens and 20s across all of the region.
URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE SAN ANGELO TX
511 AM CST TUE NOV 11 2014

...A FREEZE WARNING IS IN EFFECT FOR ALL OF WEST CENTRAL TEXAS
LATE TONIGHT AND EARLY WEDNESDAY...

.EXPECT MUCH COLDER TEMPERATURES ACROSS WEST CENTRAL
TEXAS...BEHIND AN ARCTIC COLD FRONT. TEMPERATURES WILL QUICKLY
DROP TONIGHT...WITH WIDESPREAD LOW TEMPERATURES IN THE MID TO UPPER
20S.

STERLING-COKE-RUNNELS-IRION-TOM GREEN-CONCHO-CROCKETT-SCHLEICHER-
SUTTON-COLEMAN-BROWN-MCCULLOCH-SAN SABA-MENARD-KIMBLE-MASON-
INCLUDING THE CITIES OF...STERLING CITY...ROBERT LEE...BRONTE...
BALLINGER...WINTERS...MERTZON...SAN ANGELO...EDEN...OZONA...
ELDORADO...SONORA...COLEMAN...BROWNWOOD...BRADY...SAN SABA...
MENARD...JUNCTION...MASON (FREEZE WARNING ALSO INCLUDES LAMPASAS 
COUNTY, AS ISSUED BY THE FT. WORTH NWS OFFICE)
511 AM CST TUE NOV 11 2014

...FREEZE WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM CST
WEDNESDAY...

THE NATIONAL WEATHER SERVICE IN SAN ANGELO HAS ISSUED A FREEZE
WARNING...WHICH IS IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM CST
WEDNESDAY. THE FREEZE WATCH IS NO LONGER IN EFFECT.

* TEMPERATURES...FALLING INTO THE MID TO UPPER 20S AREA WIDE.

* IMPACTS: THIS WILL BE THE FIRST FREEZE OF THE SEASON FOR MANY
  LOCATIONS. THESE TEMPERATURES MAY DAMAGE COLD SENSITIVE PLANTS.
  EXPOSED PIPES MAY FREEZE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FREEZE WARNING MEANS SUB-FREEZING TEMPERATURES ARE IMMINENT OR
HIGHLY LIKELY. THESE CONDITIONS WILL KILL CROPS AND OTHER
SENSITIVE VEGETATION.

Freeze Watch issued for western Hill Country

November 10th, 2014 at 7:38 pm by under Weather

The FREEZE WATCH has been expanded south to include all counties. A widespread freeze is likely Tuesday night/Wednesday morning. Lows will be in the lower to upper 20s area-wide.
URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE SAN ANGELO TX
330 PM CST MON NOV 10 2014

...FIRST FREEZE OF THE SEASON UPCOMING...

.AN ARCTIC COLD FRONT WILL MOVE ACROSS WEST CENTRAL TEXAS
TONIGHT...BRINGING THE COLDEST AIR OF THE SEASON SO FAR TO THE
AREA. TEMPERATURES WILL QUICKLY DROP TUESDAY NIGHT...WITH
WIDESPREAD LOW TEMPERATURES IN THE LOWER TO UPPER 20S.

..OZONA...ELDORADO...SONORA...BRADY...
SAN SABA...MENARD...JUNCTION...MASON
330 PM CST MON NOV 10 2014

...FREEZE WATCH IN EFFECT FROM LATE TUESDAY NIGHT THROUGH
WEDNESDAY MORNING...

THE NATIONAL WEATHER SERVICE IN SAN ANGELO HAS ISSUED A FREEZE
WATCH...WHICH IS IN EFFECT FROM LATE TUESDAY NIGHT THROUGH
WEDNESDAY MORNING.

* TEMPERATURES...FALLING INTO THE LOWER TO UPPER 20S AREA WIDE.

* IMPACTS: THIS WILL BE THE FIRST FREEZE OF THE SEASON FOR MANY
  LOCATIONS. THESE TEMPERATURES MAY DAMAGE COLD SENSITIVE
  PLANTS. EXPOSED PIPES MAY FREEZE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FREEZE WATCH MEANS SUB-FREEZING TEMPERATURES ARE POSSIBLE.
THESE CONDITIONS COULD KILL CROPS AND OTHER SENSITIVE VEGETATION.
RESIDENTS SHOULD COVER SENSITIVE PLANTS OR BRING THEM INSIDE...
BRING PETS INSIDE OR PROVIDE ADEQUATE SHELTER...AND COVER EXPOSED
PIPES.

Polar plunge: Special Weather Statement

November 10th, 2014 at 3:00 pm by under Weather

A strong cold front will move through South-Central Texas on Tuesday, with falling temperatures in the afternoon behind it. A much colder airmass will entrench itself over the region Wednesday through Friday, with high temperatures only in the 50s on Wednesday, and mid 40s to low 50s on Thursday! A freeze is possible across the northern Hill Country Thursday morning and across Central Texas and the Hill Country Friday morning. Models have been trending colder, and there is the potential this freeze line could be moved slightly farther south and east Friday morning. Stay tuned.

A freeze is possible across the northern Hill Country Thursday morning and across Central Texas and the Hill Country Friday morning. Models have been trending colder, and there is the potential this freeze line could be moved slightly farther south and east Friday morning. Stay tuned.

From National Weather Service:

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
316 PM CST MON NOV 10 2014

LLANO-BURNET-WILLIAMSON-VAL VERDE-EDWARDS-REAL-KERR-BANDERA-
GILLESPIE-KENDALL-BLANCO-HAYS-TRAVIS-BASTROP-LEE-KINNEY-UVALDE-
MEDINA-BEXAR-COMAL-GUADALUPE-CALDWELL-FAYETTE-MAVERICK-ZAVALA-
FRIO-ATASCOSA-WILSON-KARNES-GONZALES-DE WITT-LAVACA-DIMMIT-
INCLUDING THE CITIES OF...LLANO...BURNET...GEORGETOWN...DEL RIO...
ROCKSPRINGS...LEAKEY...KERRVILLE...BANDERA...FREDERICKSBURG...
BOERNE...BLANCO...SAN MARCOS...AUSTIN...BASTROP...GIDDINGS...
BRACKETTVILLE...UVALDE...HONDO...SAN ANTONIO...NEW BRAUNFELS...
SEGUIN...LOCKHART...LA GRANGE...EAGLE PASS...CRYSTAL CITY...
PEARSALL...PLEASANTON...FLORESVILLE...KARNES CITY...GONZALES...
CUERO...HALLETTSVILLE...CARRIZO SPRINGS
316 PM CST MON NOV 10 2014

...MUCH COLDER TEMPERATURES TUESDAY THROUGH FRIDAY WITH THE FIRST
FREEZE OF THE SEASON POSSIBLE IN SOME AREAS LATER THIS WEEK...

A STRONG COLD FRONT WILL MOVE THROUGH SOUTH CENTRAL TEXAS TOMORROW
MID MORNING. AHEAD OF THE FRONT TONIGHT TEMPERATURES WILL DROP INTO
THE 50S ACROSS THE HILL COUNTRY BUT REMAIN IN THE UPPER 50S AND
LOWER 60S ALONG AND EAST OF INTERSTATE 35.

BEHIND THE COLD FRONT...TEMPERATURES WILL REMAIN TUESDAY AFTERNOON
IN THE LOWER 50S ACROSS THE HILL COUNTRY AND CENTRAL TEXAS AND
IN THE UPPER 50S TO NEAR 60 ACROSS SOUTHERN AREAS. BY WEDNESDAY
MORNING TEMPERATURES WILL DIP INTO THE MID AND UPPER 30S ACROSS
THE HILL COUNTRY AND LOW 40S ELSEWHERE. HIGHS ON WEDNESDAY WILL
ONLY BE IN THE LOW TO MID 50S....WITH IT FEELING EVEN COLDER WITH
A BRISK NORTH WIND.

EVEN COLDER TEMPERATURES ARE EXPECTED THURSDAY...WITH LOWS ACROSS
SOME LOCATIONS IN THE NORTHERN HILL COUNTRY POSSIBLY DIPPING TO
THE FREEZING MARK...AND UPPER 30S TO LOW 40S ELSEWHERE. HIGHS ON
THURSDAY WILL RANGE FROM THE MID AND UPPER 40S ACROSS THE HILL
COUNTRY AND CENTRAL TEXAS TO LOW 50S ACROSS SOUTHERN AREAS.

AT THIS TIME...FREEZING TEMPERATURES OF 28 TO 32 DEGREES ARE
EXPECTED FRIDAY MORNING ALONG AND NORTH OF A ROCKSPRINGS TO MEDINA
TO BOERNE TO JOHNSON CITY TO KILLEEN LINE. THERE IS THE
POSSIBILITY OF THIS LINE BEING EXTENDED SLIGHTLY FARTHER SOUTH IN
THE COMING DAYS...AS MODELS HAVE BEEN TRENDING COLDER. SOUTH OF
THE LINE LOW TEMPERATURES IN THE MID 30S TO AROUND 40 ARE
EXPECTED. HIGHS ON FRIDAY WILL ONLY BE IN THE LOW TO MID 50S.

SLIGHTLY WARMER TEMPERATURES ARE EXPECTED OVER THE WEEKEND...ALONG WITH
A SLIGHT CHANCE OF RAIN.

Percent chance for freezing temperatures

November 10th, 2014 at 9:17 am by under Weather

1 SPC

Above is a product released by an arm of the National Weather Service known as The Weather Prediction Center.  It is the percentage chance an area will see freezing temperatures ( at or below 32F) at that time.  We took a screen grab of the best chance we’ll have here in Central Texas for those type of numbers.

2-5 Thurs Details

Notice as we zoom into the KXAN viewing area, which we have highlighted in red, about 75% of our counties are covered.  The best chance, will occur in the Hill Co.  Probabilities on the morning of 11/14 (Friday) will range between 30% and 70%.  Make sure to prepare,bring in, or cover your sensitive plants.  Also, DONT FORGET TO BRING IN YOUR PETS!!!

Here is the SPECIAL WEATHER STATEMENT associated with the cold blast issued by the National Weather Service earlier today.

616 AM CST MON NOV 10 2014

...MUCH COLDER TEMPERATURES TUESDAY THROUGH FRIDAY WITH THE FIRST
FREEZE OF THE SEASON POSSIBLE IN SOME AREAS LATER THIS WEEK...

A STRONG COLD FRONT WILL MOVE THROUGH SOUTH-CENTRAL TEXAS TUESDAY
MORNING. AHEAD OF THE FRONT TODAY...WARM TEMPERATURES IN THE UPPER
70S TO LOW 80S AND A BREEZY SOUTH WIND.

BEHIND THE COLD FRONT...TEMPERATURES WILL FALL TUESDAY AFTERNOON
INTO THE 40S ACROSS THE HILL COUNTRY AND CENTRAL TEXAS AND INTO
THE 50S ACROSS SOUTHERN AREAS. BY WEDNESDAY MORNING TEMPERATURES
WILL DIP INTO THE MID AND UPPER 30S ACROSS THE HILL COUNTRY AND
LOW 40S ELSEWHERE. HIGHS ON WEDNESDAY WILL ONLY BE IN THE LOW TO
MID 50S....WITH IT FEELING EVEN COLDER WITH A BRISK NORTH WIND.

EVEN COLDER TEMPERATURES ARE EXPECTED THURSDAY...WITH LOWS ACROSS
SOME LOCATIONS IN THE NORTHERN HILL COUNTRY POSSIBLY DIPPING TO
THE FREEZING MARK...AND UPPER 30S TO LOW 40S ELSEWHERE. HIGHS ON
THURSDAY WILL RANGE FROM THE MID AND UPPER 40S ACROSS THE HILL
COUNTRY AND CENTRAL TEXAS TO LOW 50S ACROSS SOUTHERN AREAS.

AT THIS TIME...FREEZING TEMPERATURES OF 28 TO 32 DEGREES ARE
EXPECTED FRIDAY MORNING ALONG AND NORTH OF A ROCKSPRINGS TO MEDINA
TO BOERNE TO JOHNSON CITY TO KILLEEN LINE. THERE IS THE
POSSIBILITY OF THIS LINE BEING EXTENDED SLIGHTLY FARTHER SOUTH IN
THE COMING DAYS...AS MODELS HAVE BEEN TRENDING COLDER. SOUTH OF
THE LINE LOW TEMPERATURES IN THE MID 30S TO AROUND 40 ARE
EXPECTED. HIGHS ON FRIDAY WILL ONLY BE IN THE LOW TO MID 50S.

SLIGHTLY WARMER TEMPERATURES ARE EXPECTED OVER THE WEEKEND...ALONG WITH
A SLIGHT CHANCE OF RAIN.

 


Ex-Super Typhoon Nuri “bombs” in the Pacific

November 9th, 2014 at 5:48 pm by under Weather

What was once a 180-mph category 5 “super typhoon” in the Pacific has transitioned into an “extratropical” storm over the Bering Sea near Alaska. But as Dr. Jeff Masters explains, it hasn’t lost much strength:

(wunderground.com)

What was once Category 5 Super Typhoon Nuri bombed into one of the strongest extratropical storms ever observed in the Pacific Ocean, reaching 924 mb at 06 UTC Saturday morning–a pressure rarely achieved by an extratropical storm. Tonight, the storm is bringing 96-mph wind gusts to islands on the southwestern fringes of Alaska.

The only two Pacific storms I am aware of that compare are the October 25 – 26, 1977 storm near Dutch Harbor, Alaska that set Alaska’s all-time low pressure record (925 mb), and a storm from December 24, 1975 that hit 926 mb near 49°N 158°W. Wunderground’s weather historian Christopher C. Burt has all the details in his latest post. Thanks go to wunderblogger Steve Gregory for supplying the images below.


Figure 1. MODIS satellite image of the mighty extratropical storm Ex-Typhoon Nuri became in the Bering Sea on November 8, 2014. Image credit: NASA.

Read the rest of this entry »


Is El Niño slip-slidin’ away?

November 8th, 2014 at 1:39 pm by under Weather
The CPC/IRI ENSO forecast has dropped the likelihood of El Niño again, to 58%, despite the presence of “borderline” El Niño conditions (i.e. warmer equatorial Pacific sea surface temperature, and some reduction in rain over Indonesia). El Niño is still expected, but with less confidence. What is it about this year that may be making it harder to forecast?

Many studies, using both long-term climate model simulations and observed data, have found that ENSO changes on decadal (10-year) or longer timescales.  This low-frequency or interdecadal variability includes changes in ENSO strength (variance) and frequency (how often events re-occur).

In other words, in one decade, the pattern may be weak El Niño events followed by weak La Niña events every other year, and then the next decade the pattern may be just a handful of strong, irregularly spaced events.  These decadal shifts are largely not predictable (Wittenberg et al. 2014; if you’re interested in a lot of technical detail about the interdecadal variability of ENSO, check out the references in that article.)

In an earlier post, I discussed the start times we’ve seen in ENSO events in the past, and mentioned how in the last decade, we’ve seen events starting later in the year than in decades prior. This isn’t the only recent change in the characteristics of ENSO, though, and many scientists think we have seen a shift in low-frequency variability since around the year 2000 (e.g. Yeh et al. 2009, Lee and McPhaden 2010).  These shifts may make ENSO prediction harder for today’s state-of-the-art climate models to predict.

One example of the evidence of a change in ENSO behavior is that El Niño events since 2000 have tended toward the central Pacific flavor, and there have been more frequent, less intense events (Lee and McPhaden 2010, Hu et al. 2013). Along with weaker ENSO, we’ve observed changes in the thermocline, the line that separates the warmer upper ocean and the colder deeper waters (often identified by the depth of the 20°C layer).

The thermocline is now deeper in the western Pacific, and shallower in the eastern Pacific (Fig. 1), which means that colder waters are closer to the surface in the eastern Pacific (Wen et al. 2014).  Yet another change is that winds near the equator are more easterly, indicating a strengthening of the Pacific Walker circulation (e.g. L’Heureux et al., 2013; Sohn et al., 2013).

Thermocline/winds/El Nino schematic

Figure 1: Schematic of average thermocline position and easterly winds, pre-2000 (left) and post-2000 (right). Shading shows average sea surface anomalies during El Niño events in each of the two periods. Figure by climate.gov.

All of these changes affect the development of ENSO, and one implication of the shift in decadal (or longer) variability is that ENSO may be less predictable while this phase interdecadal variability is underway. For example, much of the predictability of ENSO is based on the slow movement of warm Pacific subsurface ocean waters. In the period prior to 2000, anomalies in the warm water volume would occur six or eight months before the start of an ENSO event. Since 2000, this lead time has shrunk to only two or three months (Fig. 2; McPhaden 2012).

WWV and Nino3.4 index

Figure 2: Warm water volume anomalies in the tropical Pacific (green) and Niño3.4 index (purple). Figure by climate.gov from CPC data.

In addition, the shift toward weaker, more centrally located El Niños is more difficult for climate models to capture (e.g. Kirtman et al., 2013; Xue et al. 2013).  The depth of the thermocline, equatorial winds, and sea surface temperatures are inextricably linked–and so the combination of certain factors results in changes in how well ENSO can be predicted.

An illustration of how weaker events are harder to predict is shown by the four “missed” events in the model prediction of the October-December ENSO index: all were weak events that the models thought would be neutral (three of these four have been since 2000). The “false alarm” forecast of 2012 was for a weaker El Niño (Niño3.4 between +0.5 and +1.0°C) that never occurred.  If an El Niño develops this year, it’s likely to be weak.

What is this 58% confidence–still close to 3-in-5 odds–based on, then? Well, surface temperature anomalies are hovering around the +0.5°C threshold, and most of the dynamical models are still calling for increasing Niño3.4 anomalies. As well, another downwelling Kelvin wave has developed (Fig. 3), which will continue to supply the central and eastern Pacific with warmer-than-average sea surface conditions.

The CFSv2 has an unusual forecast (some slight cooling in the Niño3.4 region, then increasing warm anomalies through the spring) that’s difficult to interpret. We’re still not seeing much of an atmospheric response to the surface warming, so there is now concern that if El Niño conditions are achieved, they won’t persist for the five overlapping seasons required for this to be called an El Niño event. So, we’re still calling for the development of El Niño–just with less confidence.

sea surface height anomaly from satellite data

Figure 3: Sea surface height anomalies in early November 2014. Red indicates higher-than-average heights caused by warm waters of the current downwelling Kelvin wave. Figure by NASA/JPL.  

Author: Emily Becker

References

Hu, Zeng-Zhen, Arun Kumar, Hong-Li Ren, Hui Wang, Michelle L’Heureux, and Fei-Fei Jin, 2013: Weakened Interannual Variability in the Tropical Pacific Ocean since 2000. J. Climate26, 2601–2613.

Kirtman, B., J. Infanti, and S. Larson, 2013. The diversity of El Nino in the North American Multi-Model Prediction System. U.S. Clivar Variations, 11, 18-23.

Lee, T. and M. J. McPhaden, 2010: Increasing intensity of El Niño in the central-equatorial Pacific. Geophys. Res. Lett., 37,  doi:10.1029/2010GL044007.

McPhaden, M. 2012: A 21st century shift in the relationship between ENSO SST and warm water volume anomalies. Geophys. Res. Lett., 39,  doi:10.1029/2012GL051826.

Sohn, B. J., S.-W. Yeh, J. Schmetz, and H.-J. Song (2013), Observational evidences of Walker circulation change over the last 30 years contrasting with GCM results, Clim. Dyn., 40, 1721–1732, doi:10.1007/s00382-012-1484-z

Wen, C., A. Kumar, Y. Xue, M. J. McPhaden, 2014: Changes in Tropical Pacific Thermocline Depth and Their Relationship to ENSO after 1999. J. Climate, 27, 7230 – 7249.

Wittenberg, A. T., A. Rosati, T. L. Delworth, G. A. Vecchi, and F. Zeng, 2014: ENSO Modulation: Is It Decadally Predictable? J. Climate, 27, 2667-2681.

Xue, Yan, Mingyue Chen, Arun Kumar, Zeng-Zhen Hu, and Wanqiu Wang, 2013: Prediction Skill and Bias of Tropical Pacific Sea Surface Temperatures in the NCEP Climate Forecast System Version 2. J. Climate, 26, 5358–5378.


48 hour rainfall totals

November 6th, 2014 at 1:31 pm by under Weather
Hundreds more area rainfall totals can be found on our RAINFALL PAGE. 
Rainfall impact on area roads can be found on our LOW WATER CROSSINGS PAGE.

Here is the final map of rainfall that fell over the past two days. Most areas (in orange or darker) received at least 2 inches of rain. There was a swath of rain that extended from San Antonio north into the southern Hill Country where at least 4 to 6 inches of rain was observed. The area outlined in black is the recharge zone for the Edwards Aquifer. Any rain that falls into this region is able to be absorbed into the Aquifer which is the main source of water for many South-Central Texas residents. The aquifer level is up 8 feet from just a week ago!
...48 HOUR RAINFALL REPORTS UP TO 6 AM CST THURSDAY...

LOCATION                       AMOUNT    TIME/DATE

...TEXAS...

...BASTROP...
3 W CEDAR CREEK                2.79 IN   0600 AM 11/06
RED ROCK 1.2 N                 2.52 IN   0504 AM 11/06
CEDAR CREEK BELOW BASTROP      2.39 IN   0600 AM 11/06
6 NNW CAMP SWIFT               2.37 IN   0600 AM 11/06
1 WSW ROSANKY                  2.37 IN   0600 AM 11/06
TOM MILLER DAM                 2.35 IN   0600 AM 11/06
1 NW CAMP SWIFT                2.23 IN   0608 AM 11/06
7 NNE WYLDWOOD                 2.16 IN   0600 AM 11/06
CEDAR CREEK NEAR BASTROP       2.13 IN   0600 AM 11/06
1 WSW BASTROP                  1.73 IN   0600 AM 11/06
SMITHVILLE                     1.16 IN   0610 AM 11/06
ELGIN 0.3 NE                   1.04 IN   1028 PM 11/05
3 WSW CIRCLE D-KC ESTATE       0.85 IN   0600 AM 11/06

...BLANCO...
10 WNW JOHNSON CITY            3.04 IN   0600 AM 11/06
 Read the rest of this entry »

Persistent rainfall will continue flash flood threat

November 5th, 2014 at 2:02 am by under Weather
Click for latest Composite Reflectivity radar image from the Austin/San Antonio, TX radar and current weather warnings

A Flash Flood Watch is in effect for all of South Central Texas through Noon as a cold front and upper level disturbance will interact with ample moisture in place to produce rainfall across the area. most areas will see 2 to 4 inches with isolated totals of 6 to 7 inches possible. Locally Heavy Rainfall will lead to the possibility of flash flooding.
FLOOD WATCH
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1050 PM CST TUE NOV 4 2014

...HEAVY RAINFALL AND FLASH FLOODING POSSIBLE ACROSS SOUTH
CENTRAL TEXAS AND THE HILL COUNTRY THROUGH WEDNESDAY MORNING...

.AN UPPER LEVEL STORM SYSTEM AND COLD FRONT IS INTERACTING WITH
UNSEASONABLY HIGH ATMOSPHERIC MOISTURE ENHANCED BY TROPICAL STORM
VANCE WHICH IS BRINGING LOCALLY HEAVY RAINFALL TO SOUTH CENTRAL TEXAS
AND THE HILL COUNTRY OVERNIGHT TONIGHT THROUGH WEDNESDAY MORNING.  Read the rest of this entry »