558
FOUS30 KWBC 231819
QPFERD
EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
119 PM EST FRI JAN 23 2026
DAY 1
VALID 16Z FRI JAN 23 2026 - 12Z SAT JAN 24 2026
...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL IN AND NEAR THE
TEXAS HILL COUNTRY & IN SOUTH FLORIDA...
SOUTH-CENTRAL TX/TX HILL COUNTRY...
MAINTAINED LOW-END/5% PROBABILITIES FOR A CONDITIONAL FLASH FLOOD
RISK ACROSS THE HILL COUNTRY TODAY AND TONIGHT. OVERRUNNING SHOWERS
HAVE DEVELOPED NORTH OF A FRONT ACROSS SOUTH-CENTRAL TX. THE 12Z
HREF/06Z REFS GUIDANCE INDICATES THAT SOME CONVECTIVE DEVELOPMENT
IS POSSIBLE THIS AFTERNOON, BUT A BULK OF THE ACTIVITY IS EXPECTED
OVERNIGHT. THE ATMOSPHERE BECOMES INCREASINGLY SATURATED DURING THE
DAY TODAY, AND A POOL OF 500-1000 J/KG OF MU CAPE BROADENS ACROSS
SOUTH TX. DURING THE AFTERNOON AND EVENING, THE 850 HPA INFLOW
BACKS AND INCREASES, WHICH LED TO CONVECTIVE DEVELOPMENT CLOSER TO
THE RIO GRANDE WITHIN THE HREF ENSEMBLE SUITE. ENOUGH EFFECTIVE
BULK SHEAR IS AVAILABLE FOR CONVECTIVE ORGANIZATION. ADJUSTMENTS
TO THE AREA USED THE 06Z REFS/12Z HREF 3"+ PROBABILITY FOOTPRINT.
WE STILL HAVE DISCORDANCE BETWEEN THE TWO, WITH THE REFS SHOWING A
MUCH HIGHER CHANCE OF 3"+ THAN THE HREF. ACTIVITY WOULD BE ELEVATED
AND HAS SOME CHANCE OF REPEATING/TRAINING BEFORE MOVING ALONG.
PARTS OF THIS AREA HAVE MINIMAL TOPSOIL, WHICH WOULD ALLOW HEAVY
RAINFALL TO MORE READILY RUN OFF.
..SOUTH FL
ACTIVITY MOVING SOUTH-SOUTHWEST OFF THE GULF STREAM JUST OFFSHORE
PALM BEACH COUNTY ALONG WITH ATTEMPTS AT A WEAK CONVECTIVE BAND
TOWARDS KEY BISCAYNE HAVE LED TO A NEW MARGINAL RISK AREA. EVEN
THOUGH 850 HPA INFLOW IS WEAK, THE FLOW ENOUGH IS STRONG ENOUGH TO
LEAD TO ~35 KTS OF EFFECTIVE BULK SHEAR IN AN ENVIRONMENT WITH
500-1000 J/KG OF ML CAPE AND PWS OF 1.5". YESTERDAY, RADAR
ESTIMATES FROM KEY BISCAYNE WERE IN THE 6" RANGE. AS A PRECAUTION,
WILL RAISE A MARGINAL RISK FOR POPULATED AREAS OF SOUTH FL. HOURLY
RAIN AMOUNTS UP TO 2" WITH LOCAL TOTALS TO 4" ARE POSSIBLE. ANY
HEAVY RAIN-RELATED ISSUES IN URBAN AREAS WOULD BE ISOLATED TO
WIDELY SCATTERED.
ROTH
DAY 2
VALID 12Z SAT JAN 24 2026 - 12Z SUN JAN 25 2026
...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS THE
IMMEDIATE NORTHWEST GULF COAST...
GUIDANCE TRENDS IN THE 12Z CYCLE LED TO FURTHER SUPPRESSION OF THE
MARGINAL RISK TO THE IMMEDIATE MIDDLE AND UPPER TX COASTS AS WELL
AS THE SOUTHWEST LA COAST AROUND TO THE MOUTH OF THE ATCHAFALAYA
BASIN OF SOUTH-CENTRAL LA. PRECIPITABLE WATER VALUES, INSTABILITY,
AND THE EFFECTIVE BULK SHEAR FORECAST STILL SUPPORT THE IDEA OF
HEAVY RAINFALL, BUT THERE'S AN INCREASING RISK THAT IT COULD OCCUR
OFFSHORE. HOURLY AMOUNTS TO 2" WITH LOCAL TOTALS TO 4" REMAIN
POSSIBLE. SHOULD THE SOUTH TO SOUTHEAST MODEL TREND CONTINUE, THE
MARGINAL RISK AREA COULD BE DROPPED ON LATER CYCLES.
ROTH
DAY 3
VALID 12Z SUN JAN 25 2026 - 12Z MON JAN 26 2026
...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS THE
INTERIOR SOUTHEAST...
MODELS ARE IN PRETTY GOOD AGREEMENT CONCERNING HEAVY RAINFALL
ACROSS INTERIOR PORTIONS OF THE SOUTHEAST. PRECIPITABLE WATER
VALUES OF ~1.25" EXIST WITHIN A COOL ATMOSPHERE, HIGH ENOUGH FOR
SATURATION TO OCCUR. LOW-LEVEL INFLOW/EFFECTIVE BULK SHEAR IS
SUFFICIENT FOR CONVECTIVE ORGANIZATION. THE BIGGEST QUESTION IS IN
REGARDS TO MU CAPE, WITH NAM GUIDANCE ADVERTISING 250-500 J/KG
OCCURRING UPSTREAM OF THE HEAVY RAINFALL. THIS SHOULD BE ENOUGH TO
SUSTAIN 1"+ HOURLY RAINFALL AMOUNTS, AT TIMES. A CHECK OF MODEL
SOUNDINGS INDICATE THE AREAS OF THE SOUTHERNMOST APPALACHIANS ARE
EXPECTED TO BE ABOVE FREEZING/AS MILD AS THE 40SF DUE TO NORTHWARD
GUIDANCE TRENDS IN THE WINTER WEATHER SYSTEM MOVING BY TO THE
NORTH, WHICH LED TO AN EXTENSION OF THE MARGINAL RISK AREA ACROSS
NORTHERNMOST GEORGIA INTO FAR WESTERN/SOUTHWESTERN NC. THESE AREAS
HAVE SIGNIFICANT RELIEF AND SHOULD BE LESS SENSITIVE TO ANY RECENT
DRYNESS. THE EXTENSION INTO THE SOUTHERNMOST APPALACHIANS WAS
AGREEABLE/COORDINATED WITH THE GSP/GREER SC FORECAST OFFICE.
ROTH
DAY 1 THREAT AREA: HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/94EPOINTS.TXT
DAY 2 THREAT AREA: HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/98EPOINTS.TXT
DAY 3 THREAT AREA: HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/99EPOINTS.TXT
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page