804
FXUS02 KWBC 191927
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
327 PM EDT FRI JUN 19 2026
VALID 12Z MON JUN 22 2026 - 12Z FRI JUN 26 2026
...HEAVY RAINFALL/FLOODING THREAT FROM THE SOUTHERN PLAINS TO THE
MID-ATLANTIC EARLY NEXT WEEK...
..OVERVIEW
AN UPPER LEVEL RIDGE WILL LINGER OVER THE SOUTHWEST WHILE MEAN
TROUGHING PERSISTS OVER THE NORTHEAST EARLY NEXT WEEK. SEVERAL
SHORTWAVE TROUGHS WILL TRACK EAST ACROSS THE NORTHERN TIER AND PUSH
FRONTAL SYSTEMS AND PRECIPITATION ACROSS THE CENTRAL AND EASTERN
U.S., ONE OF WHICH WILL BRING HEAVY RAINFALL POTENTIAL FROM THE
SOUTHERN PLAINS THE MID-ATLANTIC ON MONDAY. LATE NEXT WEEK, THE
RIDGE WILL WEAKEN AS A TROUGH PUSHES INTO THE WEST COAST, AND A
PROGRESSIVE SHORTWAVE MAY ALLOW FOR INCREASED PRECIPITATION
CHANCES ACROSS THE CENTRAL PLAINS.
..GUIDANCE/PREDICTABILITY ASSESSMENT
MODELS REMAIN GENERALLY IN GOOD AGREEMENT, ESPECIALLY EARLY IN THE
PERIOD. GIVEN A RELATIVELY FLAT UPPER LEVEL PATTERN, THERE ARE SOME
TIMING DIFFERENCES AS SHORTWAVES TRACK CROSS THE NORTHERN TIER, BUT
THE DIFFERENCES ARE PRETTY MINOR. MODEL SPREAD INCREASES MORE
SIGNIFICANTLY BY THE SECOND HALF OF NEXT WEEK AS PACIFIC ENERGY
BEGINS TO WORK ITS WAY INTO THE WEST COAST AND CUTS THROUGH UPPER
LEVEL RIDGING. THE PAST FEW RUNS OF THE GFS HAVE BEEN SHOWING A
STRONG SHORTWAVE PUSHING ACROSS THE WEST THURSDAY INTO FRIDAY,
WHICH SEEMS UNLIKELY GIVEN THE STRENGTH OF THE RIDGING EXTENDING
ACROSS THE INTERMOUNTAIN WEST AT THAT TIME. THE ECMWF, EC-AIFS,
AND CMC SHOW A MUCH WEAKER WAVE THAT IS MORE IN LINE WITH THE MODEL
CONSENSUS AND CURRENT FORECAST THINKING.
THE WPC FORECAST WAS INITIATED WITH A NEAR EVEN BLEND OF THE
AVAILABLE DETERMINISTIC GUIDANCE. BY MID-WEEK, THE GFS WAS PHASED
OUT OF THE BLEND WHILE ENSEMBLE MEANS FROM THE ECENS AND GEFS WERE
ADDED IN INCREASING AMOUNTS TO SMOOTH OUT MODEL DIFFERENCES.
..WEATHER/HAZARDS HIGHLIGHTS
A STRONG FRONTAL SYSTEM WILL PUSH SOUTH ACROSS THE CENTRAL AND
EASTERN U.S. EARLY NEXT WEEK. ANOMALOUS MOISTURE WILL POOL ALONG
THE FRONTAL BOUNDARY FROM THE SOUTHERN PLAINS TO THE MID-ATLANTIC
AND SUPPORT SHOWERS AND THUNDERSTORMS, SOME OF WHICH MAY BE STRONG
AND CAPABLE OF PRODUCING HEAVY RAINFALL. LOCALLY HEAVY RAINFALL
MAY RESULT IN ISOLATED TO SCATTERED INSTANCES OF FLASH FLOODING,
AND THE HIGHEST FLASH FLOOD RISK IS EXPECTED TO FOCUS FROM OKLAHOMA
TO WEST VIRGINIA. THE FRONT WILL PUSH SOUTH OF THE NORTHEAST AND
MID-ATLANTIC ON TUESDAY BUT WILL LINGER ACROSS THE SOUTH AND
SOUTHEAST THROUGH MID-WEEK, WHICH WILL RESULT IN CONTINUED CHANCES
FOR SHOWERS AND THUNDERSTORMS IN THESE REGIONS.
ANOTHER FRONTAL SYSTEM WILL GRADUALLY PUSH ACROSS THE NORTH-CENTRAL
U.S. AND MIDWEST MID-NEXT WEEK, WHICH WILL BRING PRECIPITATION
CHANCES FROM THE NORTHERN PLAINS TO THE MIDWEST AND GREAT LAKES.
THIS SYSTEM WILL BE WEAKER THAN THE FIRST, WITH MORE LIMITED
PRECIPITATION CHANCES. THERE MAY BE SOME POTENTIAL FOR LOCALLY
HEAVY RAINFALL LATE NEXT WEEK AS THE SYSTEM SLOWS IN THE NORTHEAST
AND ENCOUNTERS ATLANTIC MOISTURE, BUT THERE IS STILL QUITE A BIT
OF UNCERTAINTY WITH THIS SYSTEM AT THAT TIME.
AN UPPER LEVEL SHORTWAVE IS EXPECTED TO CUT THROUGH THE WEST AND
EMERGE IN THE GREAT PLAINS LATE NEXT WEEK, WHICH LOOKS LIKE IT
COULD BRING A CHANCE OF HEAVY RAINFALL TO THE CENTRAL PLAINS
THURSDAY INTO FRIDAY. THIS WAVE SHOULD CREATE UNSTABLE CONDITIONS
IN A WARM, MOIST AIR MASS THAT WOULD LIKELY BE CONDUCIVE FOR
THUNDERSTORMS WITH HEAVY RAINFALL. THE STRENGTH OF THIS FEATURE IS
HIGHLY UNCERTAIN AT THIS TIME, WHICH MAY AFFECT PRECIPITATION
CHANCES AND HEAVY RAINFALL POTENTIAL.
GENERALLY NEAR TO BELOW NORMAL TEMPERATURES APPEAR LIKELY FOR MUCH
OF THE EASTERN TWO-THIRDS OF THE COUNTRY THROUGH THE THE MIDDLE OF
THE WEEK, WITH A SLIGHT MODERATION BY THE END OF THE WEEK. THE
HIGHEST HEAT AND HUMIDITY WILL BE CONFINED TO TEXAS, NEAR THE GULF
COAST, AND FLORIDA WHERE HEATRISK VALUES WILL GENERALLY BE BETWEEN
MODERATE AND MAJOR (WITH SOME LOCALLY EXTREME VALUES POSSIBLE).
MEANWHILE, ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS WILL
PREVAIL ACROSS THE WEST WITH HIGHS GRADUALLY CLIMBING FURTHER INTO
THE 100S-110S IN THE DESERT SOUTHWEST. ABOVE NORMAL TEMPERATURES
WILL SPREAD FROM THE NORTHWEST INTO THE GREAT BASIN/ROCKIES BY
MIDWEEK.
DOLAN/HAMRICK
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
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