460
FXUS01 KWBC 242021
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
320 PM EST WED DEC 24 2025
VALID 00Z THU DEC 25 2025 - 00Z SAT DEC 27 2025
...LIFE-THREATENING FLASH FLOODING CONTINUES OVER SOUTHERN
CALIFORNIA TODAY AND TOMORROW; HEAVY MOUNTAIN SNOW AND HIGH WINDS
ALSO ONGOING...
...IMPACTFUL WINTRY WEATHER TO SPREAD FROM THE UPPER MIDWEST INTO
THE MID-ATLANTIC/NORTHEAST FRIDAY...
...UNSEASONABLE, RECORD BREAKING WARM WEATHER CONTINUES ACROSS THE
NATION'S MID-SECTION THROUGH CHRISTMAS INTO THIS WEEKEND...
THIS AFTERNOON, AN ANALYSIS OF OUR WEATHER PATTERN ACROSS THE
LOWER 48 HIGHLIGHTS AN ANOMALOUS MID-LEVEL HIGH PRESSURE RIDGE
ANCHORED OVER THE NATION'S HEARTLAND, WHICH IS FLANKED BY AN
EQUALLY AMPLIFIED TROUGH OVER THE EASTERN PACIFIC. UNFORTUNATELY,
THIS CONFIGURATION WILL MAINTAIN LIFE-THREATENING ATMOSPHERIC
RIVER CONDITIONS FOCUSED OVER SOUTHERN CALIFORNIA THROUGH
CHRISTMAS DAY, WHERE WIDESPREAD FLASH FLOODING IS UNDERWAY AMID
PERSISTENT 0.5" TO 1"/HOUR RAINFALL RATES. ACCORDINGLY, A RARE
HIGH RISK OF EXCESSIVE RAINFALL REMAINS IN EFFECT THROUGH TOMORROW
MORNING OVER SOUTHERN CALIFORNIA, WHICH INCLUDES THE LOS ANGELES
METROPOLITAN AREA. FLASH/URBAN FLOODING ASIDE, THE BARRAGE OF
HEAVY RAINFALL WILL ALSO LEAD TO DANGEROUS ROCK/MUD SLIDES ACROSS
SOUTHERN CALIFORNIA THROUGH CHRISTMAS DAY. USERS IN THE AFFECTED
AREA ARE ENCOURAGED TO HAVE MULTIPLE WAYS OF RECEIVING WARNING
INFORMATION, NEVER DRIVE THROUGH FLOODED ROADS, AND BE AWARE THAT
THE THRESHOLD FOR THE AFOREMENTIONED IMPACTS WILL DECREASE AS
ADDITIONAL RAIN FALLS THROUGH TOMORROW. WIDESPREAD POWER OUTAGES
AND TREE DAMAGE ARE ALSO TO BE EXPECTED, OWING TO THE COMBINATION
OF STRONG WIND GUSTS AND SATURATED SOILS ACROSS THE AREA. OUTSIDE
OF THE HIGH RISK, ADJACENT AREAS IN NORTHERN/CENTRAL CALIFORNIA
(INCLUDING THE BAY AREA) AND SOUTHERN NEVADA (INCLUDING LOS VEGAS)
CAN ALSO EXPECT SCATTERED INSTANCES OF FLASH FLOODING THROUGH
TOMORROW. IN THE MOUNTAINS OF THE SIERRA NEVADA, SNOWFALL TOTALS
MEASURED IN FEET WILL ENSURE TRAVEL OVER PASSES IS IMPOSSIBLE
THROUGH THIS WEEK.
MEANWHILE, WINTRY WEATHER IS FORECAST TO RACE ACROSS PORTIONS OF
THE UPPER-MIDWEST AS A DEVELOPING FRONTAL LOW MIGRATES EASTWARD
FROM THE DAKOTAS INTO THE UPPER GREAT LAKES EARLY FRIDAY MORNING.
AN INFLUX OF WARM AIR DRAWN NORTHWARD ATOP A SHALLOW SUB-FREEZING
AIRMASS WILL LEAD TO INCREASING COVERAGE OF IMPACTFUL FREEZING
RAIN ALONG THE NORTHERN FLANK OF THIS LOW TRACK FROM NORTHERN
MINNESOTA INTO THE OHIO VALLEY, MID-ATLANTIC, AND NORTHEAST BY
FRIDAY EVENING. AS OF THIS AFTERNOON, FREEZING RAIN AMOUNTS ARE
EXPECTED TO FOCUS ALONG A LINE ROUGHLY FROM LOWER MICHIGAN
(INCLUDING DETROIT) INTO NORTHWEST PENNSYLVANIA, WHERE UPWARDS OF
A QUARTER OF AN INCH OF ICE IS FORECAST. HOWEVER, AREAS IN THE
CENTRAL APPLACHAINS AND MID-ATLANTIC (INCLUDING WASHINGTON D.C,
BALTIMORE, AND PHILADELPHIA) COULD ALSO SEE A GLAZE OF ICE FROM
THIS EVENT. OVER PORTIONS OF CENTRAL PENNSYLVANIA AND SOUTHERN NEW
YORK, 4 TO 6 INCHES OF SNOW REMAINS A POSSIBILITY. A LOOK AT THE
WATCH-WARNING MAP THIS AFTERNOON DEPICTS A SWATH OF WINTER STORM
WATCHES OVER THE NORTHEAST IN ADVANCE OF THIS EVENT, WHICH COULD
BE QUITE IMPACTFUL FOR ANY POST-HOLIDAY TRAVEL PLANS.
IN STARK CONTRAST TO THE COLD AND WINTRY WEATHER MENTIONED ABOVE,
MUCH OF THE NATION'S MID-SECTION CAN EXPECT AN UNSEASONABLY WARM
CHRISTMAS BENEATH THE MID-LEVEL RIDGE. FORECAST HIGHS FOR TOMORROW
CALL FOR TEMPERATURES IN THE 70'S AND LOW 80'S FOR THE CENTRAL AND
SOUTHERN PLAINS, WHICH IS EXPECTED TO BREAK MANY DAILY HIGH
TEMPERATURE RECORDS. IN FACT, RECORD BREAKING HIGH TEMPERATURES
ARE EXPECTED TO STICK AROUND THROUGH THE WEEKEND WITH ALL OF THE
COLD POLAR AIR RELEGATED TO THE NORTHERN TIER FOR THE TIME BEING.
ASHERMAN
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