297
FXUS02 KWBC 142000
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
400 PM EDT THU MAY 14 2026
VALID 12Z SUN MAY 17 2026 - 12Z THU MAY 21 2026
..CENTRAL U.S. HEAVY RAINFALL/RUNOFF AND SEVERE WEATHER THREAT
..GUIDANCE/PREDICTABILITY ASSESSMENT
A MID-LEVEL VORT DIGS INTO THE WEST BEGINNING EARLY NEXT WEEK,
WHILE A RIDGE AMPLIFIES OVER THE EAST. MODELS ARE IN AGREEMENT
ABOUT THIS GENERAL PATTERN OVERVIEW, HOWEVER DIFFER WHEN IT COMES
TO DETAILS AROUND TIMING AND ORIENTATION OF THE WESTERN TROUGH.
SOME MODELS INDICATE A SPLIT FLOW PATTERN DEVELOPING (CMC), WHILE
OTHERS ARE MORE PROGRESSIVE DISLODGING THE TROUGH AND PUSHING IT
OUT INTO THE CENTRAL U.S. BY MID-LATE NEXT WEEK (GFS).
A GENERAL MODEL BLEND CONSISTING OF THE AVAILABLE DETERMINISTIC
GUIDANCE WAS USED ON DAYS 3 AND 4. THINGS BECOME MORE COMPLICATED
BY DAY 5, WHEN THE DETERMINISTIC CANADIAN AND GFS MODELS BEGIN TO
DIVERGE FROM THE MODEL CONSENSUS, THEREFORE ARE REMOVED FROM THE
BLEND AND REPLACED WITH ENSEMBLE MEANS. THE ENSEMBLE MEANS ARE
GRADUALLY INCREASED IN WEIGHTING TO HANDLE THE AFOREMENTIONED
DETERMINISTIC UNCERTAINTY THROUGH DAY 7.
..WEATHER/HAZARDS HIGHLIGHTS
ENERGETIC UPPER TROUGH/DEEPENED SURFACE LOW EJECTION OVER EASTERN
CANADA WILL LAY DOWN A TRAILING FRONT WITH FROM THE NORTH-CENTRAL
U.S TO THE NORTHEAST THIS WEEKEND. MULTIPLE SHORTWAVE IMPULSE
PASSAGES, FAVORABLE RIGHT ENTRANCE REGION UPPER JET LIFT AND
MOISTURE/INSTABILITY FOCUS INTO THE UPPER MIDWEST PORTION OF THIS
FRONT MAY SUPPORT EMERGING CONVECTIVE DEVELOPMENT AND POTENTIAL FOR
LOCAL TRAINING HAS PROMPTED AN WPC EXCESSIVE RAINFALL OUTLOOK
MARGINAL RISK AREAS VALID FOR DAY 4/SUNDAY AND DAY 5/MONDAY, WITH
THE LATTER MORE EXPANSIVE AREA STRETCHING FROM THE UPPER MIDWEST
TO THE SOUTHERN PLAINS FAVORABLE CONVECTIVE PATTERN UPTICK/GROWTH.
FARTHER UPSTREAM SYSTEM ENERGIES SUBSEQUENTLY WORK INTO THE WEST
AND DOWNSTREAM UP ACROSS THE CENTRAL U.S. WITH LESS CERTAINTY THIS
WEEKEND INTO NEXT WEEK IN AMPLIFYING FLOW. PASSAGE MAY YIELD
ENHANCED WEEKEND WINDS AND WILDFIRE THREAT POTENTIAL ACROSS THE
SOUTHERN ROCKIES/HIGH PLAINS. THERE IS ALSO THEN AN INCREASING
SIGNAL THAT AMPLE PLAINS CYCLOGENESIS/FRONTOGENESIS, UPPER JET
SUPPORT AND GROWING LEAD GULF RETURN FLOW WILL FURTHER SET THE
STAGE TO FUEL AN EXPANDING CENTRAL U.S. CONVECTIVE RAINFALL/RUNOFF
AND SEVERE WEATHER THREAT PATTERN TO MONITOR AS INDICATED BY SPC.
MEANWHILE, AN EASTWARD SPREADING UPPER RIDGE WILL SPREAD WELL
ABOVE NORMAL PRE-FRONTAL TEMPERATURES ACROSS THE CENTRAL TO EASTERN
U.S. DOWNSTREAM THIS PERIOD THAT MAY SUPPORT SOME LOCAL HIGH
TEMPERATURE VALUES. TO THE SOUTH, LOW LEVEL ONSHORE FLOW WILL BRING
SHOWERS INTO FLORIDA IN PROXIMITY TO UPPER LOW DEVELOPMENT
NEAR/EAST OF THE BAHAMAS.
KEBEDE/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