270
FXUS02 KWBC 261902
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
202 PM EST WED FEB 26 2025
VALID 12Z SAT MAR 01 2025 - 12Z WED MAR 05 2025
..COAST TO COAST U.S. SOUTHERN TIER SYSTEM TO MONITOR
..OVERVIEW
WE WILL DIVE INTO MARCH TO HERALD A STEADILY PROGRESSIVE SPLIT
STREAM UPPER FLOW PATTERN OVER THE LOWER 48 STATES AND VICINITY.
AMPLIFIED NORTHERN STREAM TROUGHING OVER THE EAST WILL BE
ESTABLISHED THIS WEEKEND, BUT WILL SHIFT EASTWARD EARLY NEXT WEEK
AND REPLACED BY UPPER RIDGING. MEANWHILE, A LEAD SOUTHERN STREAM
CUTOFF LOW OVER SOUTHERN CALIFORNIA ON SATURDAY WILL DRIFT EAST AND
GET ABSORBED INTO THE LARGER SCALE FLOW INTO EARLY NEXT WEEK OVER
THE SOUTH- CENTRAL U.S.. BEHIND THIS, A DEEP TROUGH/CLOSED LOW WILL
MOVE INCREASINGLY INTO THE WEST SUNDAY/MONDAY. WEATHER/HAZARD
FOCUS WITH THIS EMERGING AND AMPLIFIED SOUTHERN STREAM SYSTEM WILL
TRACK FROM THE SOUTHWEST THROUGH THE SOUTH-CENTRAL THEN EAST-
CENTRAL PORTION OF THE NATION EARLY TO MID NEXT WEEK. THE GUIDANCE
SIGNAL HAS GROWN FOR AN ASSOCIATED AND INCREASINGLY WIDESPREAD
SWATH OF WINDY AND WET/UNSETTLED WEATHER TO MONITOR IN THESE AREAS.
..GUIDANCE/PREDICTABILITY ASSESSMENT
FORECAST CONFIDENCE IS SLOWLY GROWING FOR THE UPCOMING MEDIUM
RANGE PERIOD AS GUIDANCE CONTINUES TO GENERALLY CONVERGE UPON A
BETTER CLUSTERED OVERALL SOLUTION, ALBEIT WITH NUMEROUS LINGERING
SMALLER SCALE SYSTEM DIFFERENCES TO SORT OUT AS WE GET CLOSER IN
TIME. THIS WPC MEDIUM RANGE PRODUCT SUITE PRODUCED FROM A
COMPOSITE OF COMPATIBLE GUIDANCE FROM THE 06 UTC GFS AND 00 UTC
ECMWF/UKMET/CANADIAN MODELS FOR BEST DETAIL VALID FOR THIS WEEKEND.
00 UTC ECMWF GUIDANCE SEEMED REASONABLE AND WAS OVERALL BEST
CLUSTERED WITH THE THE AIFS AND GEFS/ECMWF/CANADIAN ENSEMBLE MEANS.
A BLEND WAS USED ALONG WITH WPC CONTINUITY.
..WEATHER/HAZARDS HIGHLIGHTS
IT GENERALLY REMAINS THE CASE THAT A CLIPPER SYSTEM SHOULD BRING A
ROUND OF PRECIPITATION TO THE GREAT LAKES AND NORTHEAST INTO
SATURDAY, WITH MODERATE SNOWFALL POSSIBLY ENHANCED BY THE LAKE
WATERS ACROSS THE UPPER GREAT LAKES, WITH MIXED PRECIPITATION JUST
TO THE SOUTH. A PERIOD OF STRONG AND GUSTY WINDS MAY LINGER INTO
SATURDAY NEAR THE GREAT LAKES ON THE BACK-SIDE OF THE SYSTEM AS
COLD AIR RUSHES IN BEHIND IT.
THE SOUTHERN STREAM UPPER LOW MOVING INTO SOUTHERN CALIFORNIA
SATURDAY AND INLAND MAY LEAD TO MODERATE PRECIPITATION INTO THE
WEST WITH MAIN FOCUS OVER CALIFORNIA, THE SOUTHWEST, AND INTO THE
SOUTH-CENTRAL U.S., WITH INCREASING RAIN CHANCES IN THE SOUTHERN
PLAINS BY EARLY NEXT WEEK AS MOISTURE INCREASES. THIS ALSO HAS A
HIGH WIND THREAT ACROSS THAT BROAD AREA. THERE APPEARS TO BE A
BETTER SIGNAL FOR THE PRECIPITATION TO SPREAD FARTHER
EAST/NORTHEAST ACROSS THE SOUTHERN PLAINS AND EASTWARD EARLY NEXT
WEEK. THE NORTHERN STREAM TROUGH MOVING THROUGH THE EASTERN PACIFIC
AND INTO THE WEST NEXT WEEKEND WILL ALSO BRING PRECIPITATION
CHANCES BACK FOR THE WEST COAST, SPREADING ACROSS THE GREAT
BASIN/ROCKIES EARLY NEXT WEEK. AS THIS TROUGH MOVES INTO THE
CENTRAL U.S. AROUND TUESDAY-WEDNESDAY NEXT WEEK, IT SHOULD TAP
MOISTURE FROM THE GULF TO FUEL MORE WIDESPREAD RAINS ACROSS THE
EAST-CENTRAL U.S.. SPC ALSO HIGHLIGHTS A THREAT FOR SEVERE WEATHER
OVER THE SOUTH-CENTRAL STATES GIVEN SUPPORT. THERE IS ALSO THE
POTENTIAL FOR MODERATE TO AT LEAST LOCALLY HEAVY RAINFALL AND WITH
AMBIENT MOIST SOIL CONDITIONS IN SOME AREAS.
MUCH ABOVE NORMAL TEMPERATURES WILL BE WELL ESTABLISHED BY ACROSS
THE WEST AND INTO THE NORTHERN/CENTRAL PLAINS. THE GREATEST
ANOMALIES WILL BE ACROSS THE NORTHERN PLAINS WITH DAYTIME HIGHS 20
TO LOCALLY 30 DEGREES ABOVE NORMAL, WITH 60S FOR HIGHS AS FAR NORTH
AS NEBRASKA/SOUTH DAKOTA. THE ABOVE NORMAL TEMPERATURES WILL
SPREAD SOUTH AND EAST, WITH THE WEST TRENDING COOLER BY EARLY NEXT
WEEK. ACROSS THE EAST, TEMPERATURES WILL VARY BETWEEN NORMAL AND
ABOVE NORMAL INTO SATURDAY, BUT BE MOSTLY BELOW NORMAL SUNDAY AND
MONDAY IN POST-FRONTAL HIGH PRESSURE BEFORE AGAIN MODERATING.
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 (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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