809
FOUS30 KWBC 182000
QPFERD
EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
300 PM EST TUE FEB 18 2025
DAY 1
VALID 16Z TUE FEB 18 2025 - 12Z WED FEB 19 2025
...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ALONG PORTIONS OF
THE CENTRAL GULF COAST...
..16Z OUTLOOK UPDATE
THE ONGOING FORECAST IS GENERALLY ON TRACK AND NO CHANGES ARE
NEEDED TO THE MARGINAL RISK AREA. MODEL CONSENSUS IS THAT
WIDESPREAD AREAS OF 1 INCH RAINFALL TOTALS ARE EXPECTED ACROSS
EAST-CENTRAL TEXAS INTO WESTERN LOUISIANA, AND HIGHER AMOUNTS (IN
THE 2-3.5 INCH RANGE) ARE EXPECTED FROM FAR SOUTHEAST TEXAS THROUGH
SOUTHEASTERN LOUISIANA ESPECIALLY IN THE 00Z-12Z PERIOD. THE
GREATEST BUOYANCY WILL BE CONFINED TO COASTAL AREAS, AND
TRAINING/REPEATING CELLS COULD RESULT IN LOCAL 1-2 INCH/HR RAIN
RATES AT TIMES AND POSE A RISK OF EXCESSIVE RUNOFF -- ESPECIALLY IF
THAT RAINFALL CAN MATERIALIZE IN/NEAR URBANIZED AREAS. NEARER-TERM
CONVECTIVE TRENDS WILL BE MONITORED FOR ANY POTENTIAL FOCUS OF
INTENSE RAINFALL RATES THAT MAY REQUIRE A SMALL SLIGHT RISK UPGRADE
-- ESPECIALLY ACROSS SOUTH-CENTRAL AND SOUTHEASTERN LOUISIANA
OVERNIGHT.
SEE THE PREVIOUS OUTLOOK BELOW FOR MORE INFORMATION.
COOK
..PREVIOUS OUTLOOK
STRENGTHENING SOUTHWESTERLY RETURN FLOW FROM THE GULF AHEAD OF AN
AMPLIFYING UPPER-LEVEL SHORTWAVE AND AN ASSOCIATED SURFACE COLD
FRONT ARE EXPECTED TO DRAW DEEPER MOISTURE INTO PORTIONS OF THE
CENTRAL GULF COAST WITH PWS CLIMBING TO 1.5"+. THIS MOISTURE,
ALONG WITH INCREASING LIFT (VIA RIGHT-ENTRANCE REGION OF 120+ KT
SUBTROPICAL JET STREAK) AND MARGINAL INSTABILITY (MU CAPE RISING TO
NEAR 500 J/KG RIGHT ALONG THE IMMEDIATE COAST) ARE LIKELY TO BE
SUFFICIENT FOR A RELATIVELY SHORT PERIOD OF HEAVY RAINFALL RATES
(CONCENTRATED BETWEEN 00-09Z, AND LASTING FOR AROUND 3 HOURS TOTAL
AT ANY ONE LOCALITY). WHILE THE POTENTIAL FOR TRAINING STORMS LOOKS
RELATIVELY LOW (WITH INSTABILITY LARGELY LACKING PRIOR TO THE
ARRIVAL OF THE PROGRESSIVE STORMS ALONG THE FRONT), CHANCES FOR ANY
ISOLATED FLASH FLOODING APPEAR MAXIMIZED IN THE VICINITY OF LAKE
CHARLES (WITH THE BEST INSTABILITY RESULTING IN HIGHEST ODDS FOR
1-2"/HR RAINFALL RATES, AND LOCALIZED TOTALS OF 2-4" OVER A 3-HR
PERIOD). ELSEWHERE (AND PARTICULARLY FARTHER NORTH FROM THE
IMMEDIATE COASTLINE) RATES WILL LIKELY STRUGGLE TO SURPASS 1"/HR
WITH A LACK OF INSTABILITY, THOUGH IN SOME PLACES THESE BRIEF
DOWNPOURS MAY BE ENOUGH TO CAUSE LOCALIZED EXCESSIVE RAINFALL
(PARTICULARLY INTO PORTIONS OF EAST-CENTRAL TX AND WEST-CENTRAL LA
WHERE ANTECEDENT CONDITIONS ARE WETTER, ESPECIALLY COMPARED TO
RELATIVELY DRY ANTECEDENT CONDITIONS IN SOUTH-CENTRAL LA).
CHURCHILL
DAY 2
VALID 12Z WED FEB 19 2025 - 12Z THU FEB 20 2025
THE PROBABILITY OF RAINFALL EXCEEDING FLASH FLOOD GUIDANCE IS LESS
THAN 5 PERCENT.
ORRISON
DAY 3
VALID 12Z THU FEB 20 2025 - 12Z FRI FEB 21 2025
THE PROBABILITY OF RAINFALL EXCEEDING FLASH FLOOD GUIDANCE IS LESS
THAN 5 PERCENT.
ORRISON
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