705
FXUS02 KWBC 081900
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
200 PM EST SAT FEB 8 2025
VALID 12Z TUE FEB 11 2025 - 12Z SAT FEB 15 2025
...ACTIVE WEATHER PATTERN ON TAP FOR THE MEDIUM RANGE PERIOD WITH
PERIODS OF HEAVY RAIN AND WINTER WEATHER ACROSS PARTS OF THE WEST
AND THE CENTRAL-EASTERN U.S....
..OVERVIEW
MODELS AND ENSEMBLES CONTINUE TO ADVERTISE A VERY ACTIVE PATTERN
DURING THE TUESDAY-SATURDAY PERIOD. SHORTWAVE ENERGY EMERGING FROM
THE WEST/PLAINS AND ASSOCIATED FRONTAL WAVES WILL LIKELY FOCUS AN
AXIS OF HEAVY RAINFALL AND FLOODING CONCERNS OVER PARTS OF THE
SOUTHEASTERN QUARTER OF THE LOWER 48 EARLY-MID WEEK WITH SNOW
FARTHER NORTH FROM THE CENTRAL PLAINS INTO THE NORTHEAST TUESDAY
INTO THURSDAY. A WINTRY MIX WILL BE POSSIBLE BETWEEN THE RAIN/SNOW
AREAS. THEN DURING THE LATTER HALF OF THE WEEK A PACIFIC SYSTEM
SHOULD BRING AREAS OF SIGNIFICANT RAIN AND MOUNTAIN SNOW TO PARTS
OF THE WEST. THIS SYSTEM MAY REACH FAR ENOUGH EAST TO DEVELOP
PRECIPITATION OVER THE CENTRAL/EASTERN U.S. ONCE AGAIN BY NEXT
SATURDAY. EXPECT WELL BELOW NORMAL TEMPERATURES TO PERSIST OVER THE
NORTHWEST AND INTO THE NORTHERN-CENTRAL PLAINS TUESDAY-THURSDAY.
THE WEST SHOULD SEE SOME MODERATION LATE WEEK INTO THE WEEKEND AS
THE REGION SEES GREATER INFLUENCE FROM PACIFIC FLOW. THE
CENTRAL/SOUTHERN PLAINS WILL BRIEFLY TREND WARMER LATE IN THE WEEK
BUT EXPECT THE COLD AIR STILL OVER THE NORTHERN PLAINS TO PUSH
SOUTHWARD AGAIN ON SATURDAY. THE GREATEST NUMBER OF DAYS WITH ABOVE
NORMAL TEMPERATURES WILL LIKELY BE OVER THE GULF COAST AND FAR
SOUTHEAST.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE LATEST MODEL GUIDANCE CONTINUES TO SHOW OVERALL GOOD AGREEMENT
ON THE LARGE SCALE PATTERN, BUT PLENTY OF UNCERTAINTY IN THE
DETAILS. EARLY ON, THE 00Z CMC WAS FASTER AND SHARPER WITH LEADING
ENERGY INTO THE NORTHWEST AROUND WEDNESDAY, AND FASTER WITH THE
SURFACE LOW INTO THE MID-ATLANTIC/NORTHEAST LATER IN THE WEEK. THE
12Z RUN TODAY THOUGH DID SLOW DOWN BUT IS STILL ON THE
STRONGER/SHARPER SIDE. IT WAS NOT PREFERRED FOR THE EARLY MORNING
MEDIUM RANGE BLEND, SO THE WPC PROGS ARE A BLEND OF THE ECMWF AND
GFS WITH THE UKMET.
OTHERWISE, THE NEXT SHORTWAVE MOVES INTO THE WEST LATE WEEK AND
INTO THE SOUTHERN PLAINS NEXT WEEKEND. GUIDANCE AGREES ON THE
PRESENCE, BUT SOME DISAGREEMENT IN THE DETAILS AND STRENGTH WHICH
COULD TAKE UNTIL THE SHORTRANGE TO RESOLVE THESE DETAILS. PREFERED
A BLEND OF THE ECMWF AND GFS WITH THE ENSEMBLE MEANS TO HELP SMOOTH
THE DIFFERENCES FOR THE LATER PERIOD WPC FORECAST BLEND.
..WEATHER/HAZARDS HIGHLIGHTS
RAPID PROGRESSION OF A LEADING WAVE AND THE APPROACH OF A STRONGER
SHORTWAVE FROM THE WEST WILL MAINTAIN A WAVY FRONTAL BOUNDARY OVER
THE SOUTH DURING TUESDAY-WEDNESDAY, ESSENTIALLY PARALLEL TO
SOUTHWESTERLY FLOW ALOFT, AND INTERACTING WITH ANOMALOUS MOISTURE.
GUIDANCE HAS BEEN SIGNALING THE POTENTIAL FOR EXCESSIVE RAINFALL
WITH FLASH FLOOD POTENTIAL DURING THIS TIME FRAME IN RECENT DAYS
AND CONTINUES TO REFINE THE EXPECTED AXIS OF HEAVIEST RAINFALL IN
SUCCESSIVE RUNS. THE DAY 4 EXCESSIVE RAINFALL OUTLOOK VALID ON
TUESDAY CONTINUES AN EXPANSIVE SLIGHT RISK FROM THE LOWER
MISSISSIPPI VALLEY INTO THE TENNESSEE VALLEY/SOUTHERN APPALACHIANS
WITH ONLY SLIGHT ADJUSTMENTS NEEDED THIS CYCLE. DID EXTEND THE
MARGINAL RISK NORTH AND EASTWARD MORE INTO THE SOUTHERN MID-
ATLANTIC. THE FAVORED AREA FOR HEAVY RAINFALL ON DAY 5 WEDNESDAY
COMES CLOSE TO OVERLAPPING THIS REGION, SHIFTING ONLY A FRACTION
EAST/NORTHEAST, WITH A SLIGHT RISK AGAIN INDICATED. RAINFALL FROM
THE PREVIOUS DAY WOULD MAKE THIS REGION INCREASINGLY SENSITIVE TO
ADDITIONAL RAINFALL. EASTERN U.S. LOW PRESSURE TRACKING
NORTHEASTWARD ON THURSDAY SHOULD DRAG A COLD FRONT THROUGH THE
SOUTHEAST, WITH ASSOCIATED RAIN TRENDING LESS INTENSE.
THE NORTHERN SIDE OF THE PRECIPITATION SHIELD MAY CONTAIN ROUNDS
OF POTENTIALLY DISRUPTIVE WINTRY PRECIPITATION NEXT WEEK. THE
FAVORED BAND FOR WINTER WEATHER SHOULD EXTEND FROM THE CENTRAL
PLAINS THROUGH THE MIDDLE MISSISSIPPI VALLEY, OHIO VALLEY, CENTRAL
APPALACHIANS, AND MID-ATLANTIC/NORTHEAST WHERE MOISTURE
OVERRUNNING SOUTHERN TIER FRONTS WILL INTERACT WITH COLD AIR.
50+ PERCENT PROBABILITIES FOR A QUARTER INCH OF LIQUID EQUIVALENT
SNOW/SLEET REMAIN IN PLACE FOR THE CENTRAL APPALACHIANS TO MID-
ATLANTIC BUT WITH SOME SLIGHT SOUTHERN SHIFT OF THE OVERALL
PROBABILITIES FOR TUESDAY TO WEDNESDAY MORNING. MEANWHILE SLEET
AND FREEZING RAIN ARE POSSIBLE BETWEEN THE CHANCES FOR HEAVY RAIN
TO THE SOUTH AND SNOW TO THE NORTH. STAY TUNED FOR REFINEMENTS TO
THE FORECAST AS THE PLACEMENT, AMOUNT, AND TYPE OF PRECIPITATION
REMAINS UNCERTAIN AT ANY INDIVIDUAL LOCATION. THE NEXT WAVE,
REACHING THE EAST ON THURSDAY, SHOULD PRODUCE A SOMEWHAT FARTHER
NORTHWARD BAND OF SNOW, FROM THE MIDWEST INTO THE NORTHERN MID-
ATLANTIC AND NORTHEAST.
AFTER A FAIRLY DRY PERIOD EARLY IN THE WEEK, EXPECT A PACIFIC
SYSTEM TO SPREAD POTENTIALLY SIGNIFICANT RAIN AND MOUNTAIN SNOW
INTO THE WEST AFTER MIDWEEK. FOR THE DAY 5 ERO PERIOD WEDNESDAY-
WEDNESDAY NIGHT, MODELS CONTINUE TO SHOW SOME VARIABILITY IN
PRECIPITATION AMOUNTS REACHING CALIFORNIA. MAINTAINED A MARGINAL
RISK AREA ALONG THE NORTHERN HALF TO TWO-THIRDS OF THE CALIFORNIA
COAST AND EXTENDED IT INTO SOUTHERN CALIFORNIA GIVEN INCREASED
SENSITIVITIES. AFTER EARLY THURSDAY EXPECT MOISTURE TO CONTINUE
THROUGH THE WEST, WITH THIS SYSTEM LIKELY EMERGING INTO THE PLAINS
NEXT SATURDAY AND DEVELOPING ANOTHER AREA OF VARIOUS PRECIPITATION
TYPES OVER THE CENTRAL/EASTERN U.S.
NORTHWESTERN AND NORTH-CENTRAL PARTS OF THE LOWER 48 WILL SEE
COLDER THAN AVERAGE TEMPERATURES NEXT WEEK. THE COLD WILL BE
ESPECIALLY PRONOUNCED ACROSS MONTANA AND NORTH DAKOTA EARLY IN THE
WEEK, WITH LOWS FORECAST TO BE IN THE -10S AND -20S, ALONG WITH
SOME BELOW ZERO HIGHS. COLDER THAN AVERAGE TEMPERATURES WILL SPREAD
SOUTH BEHIND A COLD FRONT NEXT WEEK, DISPLACING UNSEASONABLE
WARMTH ACROSS THE SOUTHERN TIER DURING THE WEEKEND. WARMER THAN
AVERAGE TEMPERATURES SHOULD BE LIMITED TO FLORIDA AND THE ADJACENT
SOUTHEAST BY MIDWEEK. INTRODUCTION OF PACIFIC FLOW SHOULD PROMOTE A
MODERATING TREND OVER THE WESTERN-CENTRAL U.S. BY NEXT FRIDAY (BUT
REMAINING QUITE COLD OVER THE NORTHERN PLAINS). LOW PRESSURE
EMERGING OVER THE PLAINS BY NEXT SATURDAY WILL HELP TO PULL DOWN
THE LINGERING NORTHERN PLAINS COLD AIR BACK DOWN INTO THE CENTRAL
PLAINS. AT THE SAME TIME, PARTS OF THE EAST SHOULD BEGIN TO TREND
SOMEWHAT WARMER.
RAUSCH
ADDITIONAL 3-7 DAY HAZARD INFORMATION CAN BE FOUND ON THE WPC
MEDIUM RANGE HAZARDS OUTLOOK CHART AT:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
WPC MEDIUM RANGE 500MB HEIGHTS, SURFACE SYSTEMS, WEATHER GRIDS,
QUANTITATIVE PRECIPITATION FORECAST (QPF), EXCESSIVE RAINFALL
OUTLOOK (ERO), WINTER WEATHER OUTLOOK (WWO) PROBABILITIES, HEAT
INDICES, AND KEY MESSAGES CAN BE ACCESSED FROM:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST500_WBG.GIF
HTTPS://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST_WBG_CONUS.GIF
HTTPS://WWW.WPC.NCEP.NOAA.GOV/5KM_GRIDS/5KM_GRIDSBODY.HTML
HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/DAY4-7.SHTML
HTTPS://WWW.WPC.NCEP.NOAA.GOV/#PAGE=ERO
HTTPS://WWW.WPC.NCEP.NOAA.GOV/WWD/PWPF_D47/PWPF_MEDR.PHP?DAY=4
HTTPS://WWW.WPC.NCEP.NOAA.GOV/HEAT_INDEX.SHTML
HTTPS://WWW.WPC.NCEP.NOAA.GOV/#PAGE=OVW
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