309
FXUS02 KWBC 270755
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
355 AM EDT FRI MAR 27 2026
VALID 12Z MON MAR 30 2026 - 12Z FRI APR 03 2026
..OVERVIEW
QUASI-ZONAL FLOW WILL PREVAIL ACROSS THE LOWER 48 EARLY NEXT WEEK,
THOUGH A COUPLE OF SHALLOW FEATURES WILL CAUSE SOME WEATHER
IMPACTS. A SHORTWAVE MOVING THROUGH THE NORTHERN TIER SHOULD PUSH A
WAVY FRONTAL SYSTEM AHEAD OF IT, BRINGING COOLING TEMPERATURES AND
PRECIPITATION FOR THE MIDWEST/OHIO VALLEY/NORTHEAST. MEANWHILE,
SOUTHERN STREAM UPPER RIDGING ACROSS THE SOUTHEAST WILL CAUSE ABOVE
AVERAGE TEMPERATURES. THE PATTERN IS FORECAST TO AMPLIFY AS THE
WEEK PROGRESSES AS MULTIPLE TROUGHS COME INTO THE WEST, CONTINUING
UNSETTLED WEATHER THERE. ADDITIONAL MOISTURE COULD FOCUS OVER THE
EAST-CENTRAL U.S. LATER NEXT WEEK AHEAD OF THE WESTERN TROUGHING.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE FIRST FORECAST CHALLENGE DURING THE MEDIUM RANGE PERIOD WILL
BE THE TIMING OF A SHORTWAVE AND SURFACE LOW/FRONTAL SYSTEM MOVING
INTO THE CENTRAL U.S. AROUND TUESDAY-WEDNESDAY MOVING SOUTH AND
EAST WITH TIME. FOR THE 12Z/18Z (3/26) MODEL CYCLE, THERE WAS AMPLE
MODEL SPREAD WITH THESE FEATURES AND THE RESULTANT TEMPERATURES.
GENERALLY, THE GFS AND GEFS WERE MUCH SLOWER THAN CONSENSUS AND NOT
PREFERRED (ESPECIALLY THE 12Z RUNS), THE DETERMINISTIC ECMWF WAS
ON THE FAST SIDE, AND THE EC ENSEMBLE MEAN AND THE AIFS/AIGFS
SEEMED LIKE A GOOD MIDDLE GROUND. DID NEED TO ADJUST THE NBM TO BE
COOLER IN THE CENTRAL U.S. FOR HIGHS TUESDAY AND WEDNESDAY BECAUSE
THE NBM SEEMED TO FAVOR THE GFS SUITE MORE THAN PREFERRED.
FORTUNATELY THE 00Z MODEL CYCLE IS TRENDING MORE FAVORABLY TOWARD A
CONSENSUS (THOUGH THE 00Z CMC IS ON THE SLOW SIDE), SO HOPEFULLY
FUTURE MODEL BLENDS LIKE THE NBM WILL LOOK REASONABLE.
THEN, MODELS SHOW A SOUTHERN STREAM SHORTWAVE MOVING EAST INTO
CALIFORNIA LATE TUESDAY AND ACROSS THE SOUTHWEST WEDNESDAY. A
LARGER NORTHERN STREAM UPPER LOW WILL DIVE THROUGH THE NORTHEAST
PACIFIC WEDNESDAY AND REACH THE PACIFIC NORTHWEST BY THURSDAY. GFS
RUNS, INCLUDING THE NEWEST 00Z RUN, SEEM TO BE FAST OUTLIERS WITH
THIS TROUGH/LOW, ESPECIALLY CONSIDERING THE AIGFS IS SLOWER THAN
THE GFS ITSELF. CMC RUNS SEEMED A BIT SLOW, WHILE THE MIDDLE GROUND
ECMWF AND THE AI GUIDANCE WAS PREFERRED.
THE WPC FORECAST WAS BASED ON A MULTI-MODEL BLEND EARLY IN THE
PERIOD, BUT INCREASED THE PROPORTION OF THE FAVORED EC ENSEMBLE
MEAN AND THE AIFS AS THE PERIOD PROGRESSED.
..WEATHER/HAZARDS HIGHLIGHTS
A LOW PRESSURE/FRONTAL SYSTEM TRACKING THROUGH THE NORTH-CENTRAL
U.S. WILL BEGIN TO TAP INTO GULF MOISTURE AS IT MEANDERS EASTWARD.
PRECIPITATION IS FORECAST ACROSS PARTS OF THE MIDWEST AND OHIO
VALLEY MONDAY NIGHT INTO TUESDAY AND SPREADING INTO PARTS OF THE
NORTHEAST. THERE COULD BE A NONZERO CHANCE OF EXCESSIVE
RAINFALL/FLOODING CONCERNS WITH THIS SYSTEM, AS MOISTURE LEVELS
(PWS) COULD REACH OVER THE 95TH PERCENTILE FOR THIS TIME OF YEAR IN
PARTS OF THE MIDWEST/GREAT LAKES REGION. HOWEVER, WILL HOLD OFF ON
ANY EXCESSIVE RAINFALL AREAS IN THE DAY 5/TUESDAY ERO BECAUSE
ENSEMBLES SHOW LESS THAN 50 PERCENT PROBABILITIES FOR PRECIPITATION
TO REACH EVEN AN INCH IN 24 HOURS. THE CURRENT FORECAST AXIS FOR
HEAVY RAIN GENERALLY ACROSS LOWER MICHIGAN WHERE THE FRONT/LOW
COULD LINGER IS FARTHER NORTH AND WEST OF RECENT HEAVY RAINS OVER
THE OHIO VALLEY, SO ANTECEDENT CONDITIONS SHOULD NOT BE A CONCERN
UNLESS MODELS SHIFT. FARTHER SOUTH ALONG THE FRONT, EXPECT
CONVECTION TO BE MOVING TOO QUICKLY TO CAUSE FLOODING CONCERNS.
THEN AHEAD OF DEVELOPING UPPER TROUGHING IN THE WEST, MOIST INFLOW
SHOULD ALLOW FOR ADDITIONAL ROUNDS OF PRECIPITATION ACROSS THE
MISSISSIPPI AND OHIO/TENNESSEE VALLEYS INTO LATER NEXT WEEK. WITH
THESE SYSTEMS, THE INTERIOR NORTHEAST COULD SEE SOME SNOW AND ICE.
ACROSS THE WEST, MULTIPLE ROUNDS OF TROUGHING WILL LEAD TO
UNSETTLED WEATHER THROUGH NEXT WEEK. A ATMOSPHERIC RIVER SHOULD
TRACK ACROSS CALIFORNIA, EVEN INTO SOUTHERN CALIFORNIA, BY TUESDAY,
BUT IS CURRENTLY FORECAST TO REMAIN TOO WEAK TO CAUSE FLOODING
ISSUES. RAIN AND MOUNTAIN SNOW WILL BE COMMON ACROSS THE
INTERMOUNTAIN WEST WITH MULTIPLE ROUNDS THROUGH THE FORECAST
PERIOD. GUSTY WINDS COULD BE A CONCERN ACROSS THE INTERMOUNTAIN
WEST TO ROCKIES WITH THIS TROUGHY PATTERN.
WARMER THAN AVERAGE TEMPERATURES WILL BE COMMON ACROSS MUCH OF THE
U.S. EARLY NEXT WEEK, ESPECIALLY CENTRAL PORTIONS OF THE LOWER 48.
HIGHS COULD REACH THE 80S AS FAR NORTH AS NEBRASKA AND IOWA ON
MONDAY, AND SOME DAILY RECORDS ARE POSSIBLE. HOWEVER, THE STRONG
COLD FRONT SHOULD BRING TEMPERATURES BACK CLOSER TO AVERAGE OR
SLIGHTLY BELOW IN THE NORTH-CENTRAL U.S. TUESDAY AND WEDNESDAY.
WARMER THAN AVERAGE TEMPERATURES COULD HANG ON ACROSS THE SOUTHERN
TIER INTO PARTS OF THE EAST THOUGH, UNDER THE INFLUENCE OF A
BERMUDA HIGH. THE WEST SHOULD SEE COOLING TEMPERATURES AS THE WEEK
PROGRESSES GIVEN THE MULTIPLE ROUNDS OF TROUGHING ALOFT.
TATE
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
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page