506
FXUS02 KWBC 291822
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
119 PM EST THU FEB 29 2024
VALID 12Z SUN MAR 03 2024 - 12Z THU MAR 07 2024
...HEAVY SNOW AND HIGH WIND THREAT FOR THE WESTERN AND
NORTH-CENTRAL U.S...
..WET PATTERN FOR THE WEST COAST AND THE SOUTH
..GUIDANCE/PREDICTABILITY ASSESSMENT
AGREEMENT BETWEEN THE DETERMINISTIC SOLUTIONS IS REASONABLE ENOUGH
FOR A GENERAL MODEL BLEND SUNDAY-MONDAY WITH A LEADING SHORTWAVE
THROUGH THE NORTHERN PLAINS, AND ADDITIONAL ENERGY INTO THE WEST.
AFTER THIS, THERE ARE GROWING UNCERTAINTIES WITH COMBINATION OF
FLOW ENERGIES ACROSS CENTRAL CANADA, WITH SOME SHORTWAVE ENERGY
CLIPPING THE UPPER GREAT LAKES. THERE ARE AMPLITUDE QUESTIONS OUT
WEST MID NEXT WEEK AND ESPECIALLY WITH ANOTHER POSSIBLY STRONGER
SYSTEM INTO THE PACIFIC NORTHWEST. RUN TO RUN VARIBILITY HAS
IMPROVED TO SOME DEGREE, BUT STILL PLENTY OF UNCERTAINTY ACROSS
THE BOARD WITH RESPECT TO TIMING OF SYSTEMS WITH LOCAL
WEATHER/HAZARD IMPACTS. THE WPC BLEND FOR TODAY INCORPORATED MORE
OF THE ENSEMBLE MEANS WITH THE DETERMINISTIC GFS/ECMWF DAYS 5-7 TO
ACCOUNT FOR UNCERTAINTIES. THIS MAINTAINED GOOD AGREEMENT WITH THE
PREVIOUS WPC FORECAST AS WELL.
..OVERVIEW AND WEATHER/HAZARDS HIGHLIGHTS
A MAIN WEATHER STORY CONCERNS THE EVOLUTION OF AMPLIFIED UPPER
TROUGHING DIGGING INTO THE EASTERN PACIFIC THAT WILL SHIFT
EARNESTLY OVER THE WEST THIS WEEKEND. THIS AND
SUBSEQUENT/UNCERTAIN AND VARIED ADDITIONAL PACIFIC SYSTEMS WILL
SUPPORT MULTIPLE CHANCES FOR PERIODS OF LOCALLY MODERATE
PRECIPITATION THROUGH THE WEST COAST NEXT WEEK. THERE ARE ALSO
THREATS FOR HIGH WINDS AND HEAVY SNOW TO SPREAD FROM THE WEST
COAST STATES INLAND ACROSS THE INTERMOUNTAIN WEST TO THE ROCKIES,
ESPECIALLY FOR FAVORED TERRAIN/MOUNTAINS AS HIGHLIGHTED IN THE WPC
WINTER WEATHER OUTLOOK (WWO). VALLEY SNOWFALLS MAY DEVELOP MORE
OVER TIME AS SNOW LEVELS DECREASE WITH UPPER SYSTEM AND WAVY
FRONTAL COOLING. THIS TRANSLATION SHOULD ALSO FAVOR WINDY
WRAP-BACK SNOW DEVELOPMENT FROM THE NORTHERN PLAINS SUNDAY TO OVER
THE UPPER MIDWEST MONDAY WITHIN COLD CANADIAN AIR DUG ON THE
BACKSIDE OF THE SYSTEM. RUN TO RUN GUIDANCE CONTINUITY HAS BEEN
LESS THAN STELLAR WITH THE EVOLUTION OF THE WEATHER PATTERN
DOWNSTREAM OVER TIME, BUT PROTRACTED MOISTURE RETURN WITH WAVY AND
NOW SLOWER TO PROPAGATE MAIN FRONTS AND A LINGERING/WAVY COASTAL
FRONTS UP THE EAST COAST ALL POINT TO DEVELOPMENT OF WIDESPREAD
SHOWERS/THUNDERSTORMS FROM THE MISSISSIPPI VALLEY MONDAY THROUGH
THE EASTERN SEABOARD WEDNESDAY INTO THURSDAY, BUT WITH POSSIBLE
MAIN FOCUS OVER THE LOWER MISSISSIPPI VALLEY/CENTRAL GULF COAST
STATES MONDAY/TUESDAY. THE WPC DAY 5/MONDAY ERO INCLUDES A
MARGINAL RISK AREA ACROSS THIS REGION.
PACIFIC UPPER TROUGH AMPLIFICATION AND INLAND PROGRESSION THIS
WEEKEND WILL COOL TEMPERATURES OVER MUCH OF THE WEST, LEADING TO
THE SPREADING OF VALUES AS COLD AS 15 DEGREES BELOW NORMAL, WILL
COOLED CONDITIONS LINGERING NEXT WEEK. EXPECT MUCH ABOVE NORMAL
WARMTH WILL SPREAD ACROSS MUCH OF THE CENTRAL AND EASTERN U.S.
THIS WEEKEND INTO EARLY NEXT WEEK BEFORE MODERATING. THIS SHOULD
BE HIGHLIGHTED BY TEMPERATURES RANGING UPWARDS TO 20-30+ DEGREES
ABOVE NORMAL TO SPREAD FROM THE MISSISSIPPI VALLEY/MIDWEST/GREAT
LAKES INTO THE NORTHEAST TO AGAIN CHALLENGE DAILY RECORD VALUES
FOR DAYTIME HIGHS AND WARM OVERNIGHT LOWS.
SANTORELLI/SCHICHTEL
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, EXCESSIVE RAINFALL OUTLOOK,
WINTER WEATHER OUTLOOK PROBABILITIES, HEAT INDICES AND KEY
MESSAGES ARE AT:
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
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page