305
FXUS02 KWBC 060708
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
208 AM EST FRI MAR 6 2026
VALID 12Z MON MAR 09 2026 - 12Z FRI MAR 13 2026
...MULTI-DAY HEAVY RAIN/FLOODING AND SEVERE WEATHER FROM THE
SOUTH-CENTRAL TO EAST-CENTRAL U.S. INTO NEXT WEEK...
..PATTERN OVERVIEW
A WELL DEFINED SPLIT FLOW PATTERN ALOFT WILL CONTINUE INTO NEXT
WEEK HIGHLIGHTED INITIALLY BY A CLOSED UPPER LOW OVER BAJA
CALIFORNIA EARLY MONDAY AND A WARMING SOUTHEAST U.S. RIDGE. AS THE
UPPER LOW SHIFTS EAST INTO THE SOUTHERN PLAINS AROUND MID-WEEK,
MOISTURE WILL STREAM NORTHWARD TO FUEL WIDESPREAD SHOWERS AND
THUNDERSTORMS IN THE CENTRAL TO EASTERN U.S. ALONG A SURFACE
BOUNDARY. MEANWHILE, FLOW WILL BE PROGRESSIVE ACROSS THE NORTHERN
TIER WITH RENEWED PRECIPITATION CHANCES EACH DAY ACROSS THE
NORTHWEST. THE UPPER LOW SHOULD WEAKEN AND EVENTUALLY PHASE WITH
THE NORTHERN STREAM BY LATE WEEK, WITH UPPER RIDGING BUILDING
ACROSS THE SOUTHWEST.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE LATEST GUIDANCE CONTINUES TO SHOW GOOD AGREEMENT WITH THE
PLACEMENT OF THE UPPER LOW AS THE PERIOD BEGINS MONDAY, BUT BY
WEDNESDAY AND BEYOND SHOW QUITE A BIT OF UNCERTAINTY IN THE
STRENGTH OF THE SYSTEM AND HOW QUICKLY IT GETS ABSORBED INTO THE
LARGER SCALE FLOW. THROUGH THE 12Z/18Z GUIDANCE, THE GFS WAS ON THE
SLOWER SIDE OF THE GUIDANCE ENVELOPE, WITH THE EC/EC-AIFS ON THE
FASTER SIDE. NEW 00Z RUNS HAVE TRENDED FASTER AND SLOWER
(RESPECTIVELY), DECREASING THE OVERALL LONGITUDINAL SPREAD
SOMEWHAT. THERE ARE SOME RELATIVELY MINOR TIMING DIFFERENCES IN THE
NORTHERN STREAM FLOW AND VARIOUS CLIPPER LIKE SYSTEMS, BUT THESE
DIFFERENCES DO NOT REALLY IMPACT THE OVERALL EVOLUTION OF RESULTING
SENSIBLE WEATHER. WPC FORECAST BEGAN WITH A MULTI-MODEL COMPROMISE
FOR THE FIRST HALF OF THE PERIOD, LEANING MORE HEAVILY ON THE
ENSEMBLE MEANS THE SECOND HALF TO HELP MITIGATE THE DIFFERENCES
SEEN IN THE DETERMINISTIC GUIDANCE.
..WEATHER/HAZARDS HIGHLIGHTS
AMPLE MOISTURE AND INSTABILITY WILL CHANNEL INTO THE CENTRAL U.S.
TO FUEL WIDESPREAD THUNDERSTORMS WITH THE POTENTIAL FOR SEVERE AND
FLOODING THREATS. THIS WILL ESPECIALLY BE THE CASE OVER THE SOUTH-
CENTRAL U.S. AS WAVY FRONTAL SYSTEMS AND A FAVORABLE UPPER JET
ENHANCE AND FOCUS ACTIVITY. RUNOFF THREATS MAY ALSO BUILD WITH EACH
ROUND OF RAIN GIVEN A REPEATING PATTERN WITH TRAINING POTENTIAL. A
MARGINAL RISK AREA FOR A THREAT OF EXCESSIVE RAINFALL FOR
FLOODING/RUNOFF REMAINS IN PLACE FOR PORTIONS OF THE LOWER
MISSISSIPPI VALLEY AND TENNESSEE VALLEY ON DAY 4/MONDAY. ACTIVE
WEATHER LOOKS TO EXPAND NORTHWARD AS A COLD FRONT PUSHES EAST, WITH
A LARGE MARGINAL RISK ON THE DAY 5/TUESDAY ERO FROM THE SOUTHERN
PLAINS INTO THE MIDWEST. SPC IS ALSO HIGHLIGHTING SEVERE WEATHER
POTENTIAL IN A SIMILAR REGION FOR TUESDAY. THIS ACTIVITY RENEWS
ITSELF ACROSS THE SOUTHERN U.S. BEYOND TUESDAY, EXPANDING ALSO INTO
THE EAST-CENTRAL AND EAST MID TO LATE WEEK.
MEANWHILE, NORTHERN STREAM SYSTEMS PROGRESSING OVER SOUTHERN
CANADA AND THE U.S. NORTHERN TIER IN BROADLY CYCLONIC UPPER FLOW
WILL OFFER PERIODS OF WINTRY PRECIPITATION ALONG WITH A THREAT OF
HIGH WINDS MAINLY FROM THE CASCADES TO THE NORTHERN/CENTRAL ROCKIES
AND NORTHERN PLAINS. COLD AIR INTRUSION ACROSS THE NORTH- CENTRAL
STATES MAY ALSO SUPPORT BROAD SNOWS ON THE NORTHWEST AND NORTHERN
PERIPHERY OF EMERGING PRECIPITATION SHIELDS.
THE AMPLIFIED SOUTHEAST U.S./ATLANTIC CENTERED UPPER RIDGE WILL
PROMOTE SIGNIFICANT SPRINGTIME WARMING OVER THE CENTRAL AND EASTERN
U.S. INTO MID-WEEK WITH MODERATION BY THURSDAY FOLLOWING FRONTAL
PASSAGE. EARLY WEEK TEMPERATURES WILL BE 20-30 DEGREES ABOVE
AVERAGE, WITH 80S REACHING AS FAR NORTH AS PARTS OF THE OHIO VALLEY
AND MID- ATLANTIC. DAILY RECORDS COULD BECOME WIDESPREAD. ABOVE
NORMAL TEMPERATURES ARE ALSO EXPECTED TO GROW WITH TIME ACROSS THE
SOUTHWEST INTO THE HIGH PLAINS WITH THE NORTHWEST AND NORTHERN TIER
STATES CLOSER TO NORMAL THROUGH THE PERIOD.
SANTORELLI
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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