356
FXUS02 KWBC 070639
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
139 AM EST SAT MAR 7 2026
VALID 12Z TUE MAR 10 2026 - 12Z SAT MAR 14 2026
...MULTI-DAY HEAVY RAIN/FLOODING AND SEVERE WEATHER FROM THE
SOUTH-CENTRAL TO EAST-CENTRAL U.S. INTO NEXT WEEK...
..PATTERN OVERVIEW
THE MEDIUM RANGE PERIOD BEGINS TUESDAY WITH AN ACTIVE AND COMPLEX
SPLIT-FLOW REGIME FEATURING A CLOSED UPPER-LOW NEAR BAJA CALIFORNIA
MOVING EASTWARD AND AN AMPLIFYING TROUGH DIGGING FROM THE
NORTHWEST INTO THE CENTRAL U.S.. THE INTERACTION OF THESE TWO
FEATURES WILL RESULT IN WIDESPREAD RAINFALL, INCLUDING THE
POTENTIAL FOR SEVERE WEATHER, FROM THE SOUTH-CENTRAL U.S. INTO THE
OHIO VALLEY. SOME SNOW OR MIXED PRECIPITATION IS POSSIBLE ON THE
NORTHERN EDGE OF THE PRECIPITATION SHIELD FROM THE GREAT LAKES INTO
THE INTERIOR NORTHEAST. AN ATMOSPHERIC RIVER MAY BRING MODERATE TO
HEAVY PRECIPITATION TO THE PACIFIC NORTHWEST WEDNESDAY INTO
THURSDAY WITH HIGH WIND THREATS ESPECIALLY ACROSS THE ROCKIES AND
HIGH PLAINS.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE LATEST GUIDANCE IS SHOWING INCREASING AGREEMENT ON THE LARGE
SCALE PATTERN ACROSS THE CONUS FOR THE MEDIUM RANGE PERIOD. THE
GREATEST AREA OF UNCERTAINTY REMAINS WITH THE TIMING AND STRENGTH
OF THE BAJA CALIFORNIA UPPER LOW AS IT MOVES INTO THE SOUTHERN
PLAINS AND PHASES WITH THE NORTHERN STREAM AMPLIFYING TROUGH.
MODELS ARE GENERALLY TRENDING A BIT FASTER WITH THIS SYSTEM OVER
RECENT RUNS. DESPITE MINOR DIFFERENCES, A GENERAL BLEND OF THE
DETERMINISTIC GUIDANCE SERVED AS A GOOD STARTING POINT FOR THE
FIRST HALF OF THE FORECAST PERIOD. INCREASED WEIGHTING OF THE
ENSEMBLE MEANS FOR THE FRIDAY AND SATURDAY FORECAST TO DAMPEN
SOMEWHAT THE INDIVIDUAL DETERMINISTIC GUIDANCE AND PROVIDE A GOOD
MIDDLE GROUND TO THE FORECAST, ESPECIALLY REGARDING A DEEPER
SURFACE LOW NEAR THE GREAT LAKES/NORTHEAST LATE IN THE PERIOD.
..WEATHER/HAZARDS HIGHLIGHTS
RETURN FLOW FROM THE GULF AND INSTABILITY AHEAD OF THE BAJA UPPER
LOW WILL HELP FUEL A MULTI- DAY HEAVY RAIN EVENT WITH POTENTIAL
SEVERE THUNDERSTORMS AND FLOODING THREATS. FLOOD THREATS MAY ALSO
BUILD WITH EACH ROUND OF RAIN GIVEN A REPEATING PATTERN WITH
TRAINING POTENTIAL. A MARGINAL RISK AREA FOR EXCESSIVE RAINFALL IS
HIGHLIGHTED FROM THE SOUTHERN PLAINS INTO THE MIDWEST FOR TUESDAY.
ACTIVITY SHOULD GRADUALLY SHIFT EASTWARD ON WEDNESDAY WITH A
MARGINAL RISK ERO FROM THE LOWER MISSISSIPPI VALLEY INTO THE OHIO
VALLEY. SPC IS ALSO HIGHLIGHTING SEVERE WEATHER POTENTIAL IN
SIMILAR REGIONS FOR BOTH DAYS. RAINFALL WILL EXPAND INTO THE
EASTERN U.S. AHEAD OF THE MAIN FRONTAL BOUNDARY LATE IN THE WEEK,
BUT THE OVERALL FLOOD THREAT LOOKS LIMITED AS THE FRONTAL BOUNDARY
SHOULD BE MUCH MORE PROGRESSIVE AT THAT TIME. SOME SNOW OR WINTRY
MIX IS POSSIBLE ON THE NORTHERN EDGE OF THE PRECIPITATION SHIELD
FROM THE GREAT LAKES INTO THE INTERIOR NORTHEAST.
A COUPLE OF SHORTWAVES SHOULD KEEP THE PACIFIC NORTHWEST WET
THROUGH MUCH OF THE PERIOD. THE HEAVIEST RAINFALL SHOULD BE
ASSOCIATED WITH A MODEST ATMOSPHERIC RIVER AS IT ENTERS THE REGION
WEDNESDAY. HEAVY SNOWS ARE POSSIBLE IN THE HIGHER ELEVATIONS, WITH
EVEN SOME LIGHT RAIN/SNOW MIX POSSIBLE AT LOWER ELEVATIONS ON
TUESDAY INTO WEDNESDAY AS TEMPERATURES COULD BE COLD ENOUGH IN THE
MORNINGS.
DEEP SYSTEMS AND TIGHT PRESSURE GRADIENTS WILL SUPPORT HIGH WINDS,
ESPECIALLY FOR THE NORTHWEST-ROCKIES-HIGH PLAINS THROUGH MUCH OF
THE WEEK. GUSTY WINDS MAY ALSO ACCOMPANY THE COLD FRONT AS IT
SLIDES THROUGH THE MIDWEST AND INTO THE EAST MID TO LATE WEEK.
A SIGNIFICANT SPRINGTIME WARM-UP IS EXPECTED AHEAD OF THE FRONT
FROM THE OHIO VALLEY INTO THE NORTHEAST WITH DAYTIME HIGHS 20 TO 30
DEGREES ABOVE NORMAL WITH DAILY WIDESPREAD RECORDS. VALUES SHOULD
MODERATE BACK TOWARDS NORMAL BY FRIDAY FOLLOWING THE FRONTAL
PASSAGE. ABOVE NORMAL TEMPERATURES ARE ALSO EXPECTED TO EXPAND WITH
TIME ACROSS THE SOUTHWEST INTO THE PLAINS AND THE SOUTH WITH BELOW
NORMAL TEMPERATURES ACROSS THE FAR NORTHERN TIER.
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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