188
FXUS64 KEWX 191952
AFDEWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
152 PM CST SUN JAN 19 2025
..NEW SHORT TERM, LONG TERM, FIRE WEATHER
SHORT TERM
(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 150 PM CST SUN JAN 19 2025
KEY MESSAGES:
-WINTER STORM WARNINGS AND WINTER WEATHER ADVISORIES HAVE BEEN
ISSUED ACROSS ALL OF SOUTH-CENTRAL TEXAS FOR MONDAY NIGHT THROUGH
TUESDAY
-ACCUMULATING SNOW, SLEET, AND ICE WILL MAKE TRAVEL DIFFICULT AND
INADVISABLE WITHIN THE WARNING AREA
-COLD WEATHER ADVISORY THROUGH WEDNESDAY MORNING WITH HAZARDOUS
TEMPERATURES AND WIND CHILL VALUES
-PROTECT PEOPLE, PETS, PLANTS, AND PIPES FROM THE COLD WEATHER
-NEAR CRITICAL FIRE WEATHER CONDITIONS TODAY
SUNNY AND COLD CONDITIONS ARE EXPECTED THROUGH THE REST OF THIS
AFTERNOON WHERE DAYTIME HIGHS ONLY PEAK IN THE UPPER 30S ACROSS THE
HILL COUNTRY AND THE LOW TO MID 40S ELSEWHERE. MODERATE TO BREEZY
NORTHERLY WINDS WILL MAKE IT FEEL COLDER AS THE WIND CHILL VALUES
TOP OUT MAINLY IN THE 30S ACROSS MOST LOCATIONS. THE NORTH WINDS AND
LOW HUMIDITY RESULTS IN ELEVATED TO NEAR CRITICAL FIRE WEATHER
CONDITIONS ACROSS THE REGION TODAY. MORE DETAILS ARE FOUND BELOW IN
THE FIRE WEATHER DISCUSSION.
UNDER CLEAR SKIES AND WITH STEADY NORTHERLY WINDS, A VERY COLD NIGHT
WILL BE EXPECTED TONIGHT INTO THE MORNING OF MARTIN LUTHER KING JR
DAY. MORNING LOWS WILL DIP INTO THE TEENS ACROSS THE HILL COUNTRY
AND THE LOW TO MID 20S ELSEWHERE. WIND CHILLS WILL FALL INTO THE
UPPER SINGLE DIGITS ACROSS THE HILL COUNTRY AND INTO THE TEENS
ELSEWHERE. A COLD WEATHER ADVISORY REMAINS IN EFFECT FOR ALL
LOCATIONS.
AFTER A VERY COLD AND CLEAR START TO MARTIN LUTHER KING JR DAY, THE
CLOUDS WILL QUICKLY INCREASE FROM SOUTH TO NORTH ACROSS THE REGION
TOWARDS MIDDAY AND THROUGH THE REST OF THE AFTERNOON. THIS IS IN
RESPONSE TO THE APPROACHING UPPER LEVEL DISTURBANCE FROM THE
NORTHWEST, HELPING TO INDUCE A COASTAL SURFACE LOW/TROUGH. AS THAT
SURFACE LOW/TROUGH STRENGTHENS, IT WILL TRANSPORT MOISTURE INTO THE
AREA. THIS NOW LEADS INTO OUR WINTRY WEATHER POTENTIAL, WHICH IS
HIGHLIGHTED IN THE PARAGRAPHS BELOW. ONE FINAL NOTE FOR MONDAY, WITH
THE ARRIVING CLOUDS AND MOISTURE, DAYTIME HIGHS ARE EXPECTED TO
REMAIN IN THE 30S EXCEPT FOR LOCATIONS IMMEDIATELY LOCATED AT THE
RIO GRANDE WHERE HIGHS IN THE LOW TO MID 40S ARE MORE LIKELY.
PRECIPITATION MAY INITIALLY GET STARTED AS SOON AS THE LATTER HALF
OF THE AFTERNOON ON MONDAY, MAINLY SOUTH OF THE I-10 CORRIDOR. IT
WILL INITIALLY TAKE TIME TO MOISTEN THE ATMOSPHERE PROFILE, SO THE
EARLY RETURNS COULD BE OF VIRGA EVAPORATING PRIOR TO THE GROUND.
PRECIPITATION COULD START AS A PLAIN RAIN IN THE SOUTHERN MOST
COUNTIES BUT TRANSITION TOWARDS A WINTRY MIX AS THE PRECIPITATION
SHIELD EXPANDS NORTHWARD THROUGH THE LATE AFTERNOON. AFTER DARK AS
THE TEMPERATURES STEADILY FALL, PRECIPITATION LIKELY TRANSITIONS
INTO PRIMARILY A WINTRY MIX THROUGHOUT THE REGION. THE AXIS OF
PRECIPITATION MONDAY NIGHT INTO TUESDAY MORNING WILL PIVOT EAST-
SOUTHEASTWARD ACROSS THE REGION WITH TIME AS THE BASE OF THE UPPER
LEVEL DISTURBANCE NEARS THE REGION. AS THE TROUGH APPROACHES, THE
ATMOSPHERIC PROFILE ALOFT WILL DYNAMICALLY COOL WITH TIME TO WHERE
THE PRECIPITATION TYPE, ESPECIALLY ACROSS THE NORTHERN AND EASTERN
HALF OF THE REGION, TRANSITIONS TO MORE OF A SNOW/SLEET MIX. FARTHER
SOUTHEAST TOWARDS DEWITT COUNTY, FREEZING RAIN WILL CONTINUE,
CREATING A GREATER ICING THREAT IN THAT REGION.
FIRST, WE'D LIKE TO NOTE SOME CONCERNS REGARDING SNOW/SLEET RATIOS
AND SNOW SHAPE/TYPES. MODEL SOUNDINGS CONTINUE TO SHOW ACROSS OUR
REGION, A DRY LAYER ALOFT ACROSS THE DENDRITE GROWTH ZONE (-12 TO -
18 DEGREES) FOR MAJORITY OF THE EVENT. THE MODELS SHOW BETTER
MOISTURE CLOSER TO OR ACROSS THE DENDRITE GROWTH ZONE FARTHER EAST
AND AS YOU GET INTO THE HOUSTON CWA. ADDITIONALLY, THE ICE
CONTAINING CLOUDS WILL ALL TREND MAINLY WARMER THAN -10 DEGREES
BELOW 700 MB AND WOULD LIKELY RESULT IN A CONCENTRATION OF SOME
SUPERCOOLED LIQUID (WATER). THIS MAY HELP LEAD TO ICE RIMING ON THE
SNOW AND/OR SLEET PELLETS THAT FALL. THE COLDEST TEMPERATURES ALOFT
THAT THE FLAKES FORM ALSO ARE IN THE FAVORABLE ZONE WHERE SNOWFLAKE
TYPE MAY BE MORE IN THE COLUMN/NEEDLE TYPE THAN PLATES/DENDRITES.
THESE PROCESSES AND SLEET MIXING IN COULD LOWER SNOW TO LIQUID
RATIOS. NBM SEEMS TO SUPPORT THESE NOTIONS AND INDICATE RATIOS
GENERALLY IN THE 4:1 TO 8:1 LEVEL OVER MOST OF THE REGION.
NOW, LET'S GET DOWN TO THE ACCUMULATIONS. THIS FORECAST CALLS FOR 1
TO 2 INCHES OF SNOW AND SLEET ACCUMULATION NEAR THE I-35 CORRIDOR
AND POINTS EAST WITH SLIGHTLY HIGHER TOTALS UP TO 3 INCHES OVER
PORTIONS OF LEE, FAYETTE AND LAVACA COUNTIES. AS INDICATED ON SOME
OF THE GUIDANCE, FOR EXAMPLE THE ECMWF, SOME ISOLATED HIGHER TOTALS
WILL BE POSSIBLE WITH ANY MESOSCALE BANDING OF HEAVIER
PRECIPITATION. ELSEWHERE, UP TO AN INCH OF SNOW WILL BE POSSIBLE.
REGARDING ICE ACCRETION, AROUND A TENTH OF AN INCH WILL BE POSSIBLE
ACROSS OUR SOUTHEASTERN MOST COUNTIES AROUND DEWITT COUNTY WITH A
FEW HUNDREDTHS OF AN INCH OTHERWISE FOR LOCATIONS AROUND OR JUST
NORTH OF THE I-10 CORRIDOR. LIKE WITH SNOW/SLEET ACCUMULATION,
ISOLATED TOTALS ARE POSSIBLE IF TEMPERATURES FALL FASTER OR TREND
COLDER OR WHERE MESOSCALE BANDING OF ANY HEAVIER PRECIPITATION
OCCURS.
TRAVEL IS EXPECTED TO BECOME DIFFICULT AND INADVISABLE, ESPECIALLY
ACROSS ELEVATED BRIDGES AND OVERPASSES, AS ROADS BECOME SLICK AND
HAZARDOUS. THESE TRAVEL IMPACTS AND WITH THE LATEST FORECAST
ACCUMULATION AMOUNTS IN MIND, WE WILL ELECT TO UPGRADE PORTIONS OF
THE WINTER STORM WATCH TO A WINTER STORM WARNING ACROSS THE I-35
CORRIDOR AND POINTS EAST. A WINTER WEATHER ADVISORY WILL ALSO BE
ISSUED TO BUFFER THE WARNING ACROSS THE REMAINDER OF SOUTH-CENTRAL
TEXAS.
LONG TERM
(TUESDAY THROUGH SUNDAY)
ISSUED AT 150 PM CST SUN JAN 19 2025
KEY MESSAGES:
- THERE IS VERY HIGH CONFIDENCE (NEAR 100%) THAT HARD FREEZES WILL
OCCUR TUESDAY NIGHT, WEDNESDAY NIGHT, AND THURSDAY NIGHT. PROTECT
PEOPLE, PETS, PLANTS, AND PIPES FROM THE COLD WEATHER.
- THE POSSIBILITY OF REFREEZING OF SNOW OR ICE ACCUMULATIONS MAY
CREATE HAZARDOUS TRAVEL CONDITIONS WEDNESDAY MORNING.
- TEMPERATURES WILL SLOWLY MODERATE BACK TO NEAR SEASONAL NORMALS BY
LATE WEEK.
SNOW AND SLEET WILL BE ONGOING AT THE START OF THE LONG TERM FORECAST
PERIOD, BUT SHOULD QUICKLY END FROM WEST TO EAST BY 18Z TUESDAY.
TEMPERATURES WILL BE QUITE COLD WITH HIGHS NOT GETTING OUT OF THE
LOWER TO MIDDLE 30S, SO HAZARDOUS TRAVEL CONDITIONS ARE LIKELY TO
CONTINUE THROUGH TUESDAY AND MOST LIKELY INTO LATE WEDNESDAY MORNING
UNTIL WE GET BACK ABOVE FREEZING.
WEDNESDAY MORNING WILL LIKELY BE THE COLDEST MORNING OF THE SEASON SO
FAR, AND HOPEFULLY FOR THE REMAINDER OF THIS WINTER! WIDESPREAD LOWS
IN THE TEENS ARE LIKELY WITH SOME SPOTS PERHAPS DIPPING CLOSE TO
SINGLE DIGITS, PARTICULARLY WHERE RADIATIONAL COOLING CAN TAKE
ADVANTAGE OF FRESH SNOW COVER. SNOW IS A VERY STRONG REFLECTOR, WITH
HIGH SURFACE ALBEDO'S RESULTING IN STRONG REFLECTION OF SOLAR
RADIATION AND COLDER TEMPERATURES. WE SHOULD SEE TEMPERATURES CLIMB
BACK ABOVE FREEZING AND INTO THE 40S FOR MOST LOCATIONS, WITH AREAS
ALONG THE RIO GRANDE BACK INTO THE LOWER 50S WEDNESDAY AFTERNOON.
AT LEAST TWO MORE COLD NIGHTS WITH HARD FREEZES (TEMPS BELOW 28F) ARE
EXPECTED WEDNESDAY NIGHT AND THURSDAY NIGHT BEFORE THINGS FINALLY
REBOUND LATE WEEK. MID-LEVEL FLOW SHOULD TURN MORE ZONAL TO WEST-
SOUTHWESTERLY BY NEXT WEEKEND, ALLOWING TEMPERATURES TO GET BACK INTO
THE 60S FOR HIGHS. WE'LL BE WATCHING OUR NEXT STORM SYSTEM TRY AND
TAKE SHAPE TOWARDS THE SECOND HALF OF NEXT WEEKEND, BUT FOR NOW, THE
LONG TERM REMAINS MOSTLY DRY BEYOND TUESDAY'S WINTER STORM.
AVIATION
(18Z TAFS)
ISSUED AT 1126 AM CST SUN JAN 19 2025
A RATHER BENIGN FORECAST FOR THE NEXT 24 HOURS, THEN THINGS GET
INTERESTING AND RATHER TRICKY JUST BEYOND THIS TAF CYCLE. THAT WILL
BE ADDRESSED WITH THE 00Z ISSUANCE, PARTICULARLY AT AUS, SAT, AND
SSF. FOR NOW, HAVE OPTED TO STICK WITH THE GUSTY NORTH TO
NORTHEASTERLY WINDS THROUGH 23-00Z THEN A DROP OFF WITH NO MORE GUSTS
AFTER THAT TIME PERIOD AND WINDS SHIFTING TO MORE ENE AND EASTERLY.
CLOUDS START TO OVERSPREAD THE REGION FROM SOUTH TO NORTH BEGINNING
LATE MORNING OR AROUND NOON MONDAY WITH CEILINGS REMAINING VFR FOR
ALL SITES WITH THE EXCEPTION BEING SAT, WHERE MVFR CEILINGS DEVELOP
ALONG WITH A COMPLICATED WINTRY SETUP BY 23Z. OPTED TO INTRODUCE
FREEZING DRIZZLE AND LIGHT RAIN INTO THE FORECAST TO HINT AT THINGS
TO COME AFTER 00Z, BUT SNOW PELLET/SLEET COULD HAVE BEEN MENTIONED AS
WELL, BUT FEEL FREEZING DRIZZLE AND LIGHT RAIN WOULD BE THE
PREDOMINANT PRECIP TYPE AT ONSET FOR SAT.
FIRE WEATHER
ISSUED AT 1237 PM CST SUN JAN 19 2025
A RANGELAND FIRE DANGER DANGER STATEMENT REMAINS IN EFFECT FOR THE
COASTAL PLAINS, I-35 CORRIDOR, AND EASTERN HILL COUNTRY THROUGH 6PM
THIS EVENING. GUSTY NORTH TO NORTHEASTERLY WINDS OF 15-25 MPH ALONG
WITH MINIMUM RELATIVE HUMIDITIES BETWEEN 20-25% WILL RESULT IN
ELEVATED TO NEAR-CRITICAL FIRE WEATHER CONDITIONS IN THESE AREAS.
WINDS SHOULD RELAX AFTER 6PM WITH INCREASING HUMIDITY AND MOISTURE
EXPECTED AS WE MOVE INTO THE DAY MONDAY.
PRELIMINARY POINT TEMPS/POPS
AUSTIN CAMP MABRY 22 39 25 35 / 0 10 80 20
AUSTIN BERGSTROM INTL AIRPORT 21 39 24 34 / 0 10 80 20
NEW BRAUNFELS MUNI AIRPORT 22 39 25 35 / 0 20 80 20
BURNET MUNI AIRPORT 19 37 23 35 / 0 10 70 10
DEL RIO INTL AIRPORT 26 45 29 42 / 0 0 40 10
GEORGETOWN MUNI AIRPORT 20 38 23 34 / 0 10 70 10
HONDO MUNI AIRPORT 22 39 27 38 / 0 20 70 10
SAN MARCOS MUNI AIRPORT 20 38 24 34 / 0 20 80 20
LA GRANGE - FAYETTE REGIONAL 23 40 25 34 / 0 10 90 40
SAN ANTONIO INTL AIRPORT 24 38 26 35 / 0 20 80 20
STINSON MUNI AIRPORT 25 39 28 37 / 0 20 80 20
EWX WATCHES/WARNINGS/ADVISORIES
COLD WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR ATASCOSA-BANDERA-
BASTROP-BEXAR-BLANCO-BURNET-CALDWELL-COMAL-DE WITT-DIMMIT-EDWARDS-
FAYETTE-FRIO-GILLESPIE-GONZALES-GUADALUPE-HAYS-KARNES-KENDALL-KERR-
KINNEY-LAVACA-LEE-LLANO-MAVERICK-MEDINA-REAL-TRAVIS-UVALDE-VAL
VERDE-WILLIAMSON-WILSON-ZAVALA.
WINTER WEATHER ADVISORY FROM 6 PM MONDAY TO 6 PM CST TUESDAY FOR
BANDERA-BLANCO-BURNET-DIMMIT-EDWARDS-FRIO-GILLESPIE-KENDALL-KERR-
KINNEY-LLANO-MAVERICK-MEDINA-REAL-UVALDE-VAL VERDE-ZAVALA.
WINTER STORM WARNING FROM 6 PM MONDAY TO 6 PM CST TUESDAY FOR
ATASCOSA-BASTROP-BEXAR-CALDWELL-COMAL-DE WITT-FAYETTE-GONZALES-
GUADALUPE-HAYS-KARNES-LAVACA-LEE-TRAVIS-WILLIAMSON-WILSON.
SHORT-TERM...BRADY
LONG-TERM...MMM
AVIATION...BRADY
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