188
FXUS02 KWBC 020704
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
303 AM EDT FRI JUN 02 2023
VALID 12Z MON JUN 05 2023 - 12Z FRI JUN 09 2023
...BROAD MULTI-DAY THUNDERSTORM AND LOCAL HEAVY RAIN THREAT FROM
THE NORTHERN ROCKIES TO THE SOUTHERN GREAT PLAINS CONTINUES WELL
INTO NEXT WEEK...
..OVERVIEW
THE UPPER LEVEL PATTERN DURING THE MEDIUM RANGE PERIOD NEXT WEEK
WILL REMAIN BLOCKY AS AN ANOMALOUSLY STRONG UPPER RIDGE REMAINS
PARKED OVER THE NORTHERN PLAINS/SOUTH-CENTRAL CANADA AND INTO THE
NORTHWEST U.S.. THIS SHOULD SUPPORT PROLONGED ABOVE NORMAL
TEMPERATURES FROM THE NORTHWEST INTO THE NORTHERN PLAINS AND THE
UPPER MIDWEST AND MISSISSIPPI VALLEY. MEANWHILE, A STATIONARY
UPPER LOW OVER/NEAR CALIFORNIA WILL MAINTAIN PERIODS OF CONVECTION
OVER MUCH OF THE CENTRAL/SOUTHERN PLAINS AND ROCKIES THROUGH NEXT
WEEK. IN THE NORTHEAST, AN UPPER LOW EXITING THE REGION ON DAY 3
WILL BE REPLACED BY ANOTHER UPPER LOW WHICH DRIVES LOWERING
HEIGHTS FARTHER SOUTH INTO THE MID-ATLANTIC SOMEWHAT COOLER AND
MORE UNSETTLED CONDITIONS.
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
THE MODELS AND ENSEMBLES SHOW VERY GOOD AGREEMENT ON THE OVERALL
BLOCKY PATTERN, BUT WITH SOME DIFFERENCES IN THE DETAILS, SOME OF
WHICH WILL TAKE UNTIL THE SHORT RANGE PERIOD TO FULLY RESOLVE. IN
THE NORTHEAST, THE ECMWF REMAINS CLOSEST TO THE COAST WITH THE
UPPER LOW BUT STILL CLOSE ENOUGH TO THE CONSENSUS FOR
CONSIDERATION. THE NEXT REINFORCING WAVE OF ENERGY SHOULD DROP
INTO THE REGION TUESDAY WITH DECENT AGREEMENT FOR ANOTHER UPPER
LOW TO CLOSE OFF OVER THE NORTHEAST AND SOME DIFFERENCES IN HOW
FAR SOUTH/WEST THE BROADER TROUGH GETS. CMC REMAINS ON THE
WEAKER/MORE OPEN SIDE AND WAS NOT INCLUDED IN THE BLEND TONIGHT.
OVER CALIFORNIA, SOME MORE NOTICEABLE DIFFERENCES BEGIN TO ARISE
WITH THE POSITION OF THE UPPER LOW LATER NEXT WEEK, MOSTLY
DEPENDENT ON INFLUENCE FROM TROUGHING DROPPING SOUTH OUT OF THE
GULF OF ALASKA INTO THE NORTHWEST. A TREND TOWARDS THE ENSEMBLE
MEANS SEEMED MOST REASONABLE FOR DAYS 6 AND 7.
..WEATHER/HAZARDS HIGHLIGHTS
A CENTRAL CONTINENTAL RIDGE WITH WEAK TROUGHING OVER THE
INTERMOUNTAIN WEST KEEPS A MAINLY DIURNAL RISK FOR HEAVY SHOWERS
AND THUNDERSTORMS OVER MUCH OF THE ROCKIES/HIGH PLAINS THROUGH
TEXAS AND THE SIERRA NEVADA/GREAT BASIN NEXT WEEK. LOCALIZED FLASH
FLOOD POTENTIAL CONTINUES THROUGH AT LEAST TUESDAY GIVEN BROAD
MOIST FLOW FROM THE WESTERN GULF OF MEXICO ALONG WITH SOME
INSTABILITY. INCREASING TROPICAL PACIFIC MOISTURE FROM THE UPPER
LOW OVER CALIFORNIA EARLY NEXT WEEK BRINGS ADDITIONAL THREATS FOR
DIURNAL AND LOCALLY HEAVY SHOWERS AND STORMS FOR PARTS OF
CALIFORNIA AND THE GREAT BASIN. THE DAYS 4-5 EXCESSIVE RAINFALL
OUTLOOKS CONTINUE TO DEPICT JUST LARGE MARGINAL RISK AREAS FROM
CALIFORNIA/INTERMOUNTAIN WEST INTO THE ROCKIES AND SOUTHWARD TO
THE SOUTHERN PLAINS. EMBEDDED SLIGHT RISK AREAS MAY BECOME
NECESSARY, PARTICULARLY IF THE HEAVY RAIN FOCUS IS OVER ANTECEDENT
WET AREAS.
ELSEWHERE, A COLD FRONT THROUGH THE GREAT LAKES/UPPER MIDWEST
EARLY IN THE WEEK SHOULD FOCUS SHOWERS AND STORMS AHEAD OF IT
ACROSS THE NORTHERN PLAINS/UPPER MISSISSIPPI VALLEY. WITH DECENT
MOISTURE AND INSTABILITY, A MARGINAL RISK WAS ADDED TO THE DAYS 4
AND 5 EXCESSIVE RAINFALL OUTLOOKS. IN THE NORTHEAST, THE DEEPENING
UPPER TROUGH/LOWS SHOULD FAVOR POCKETS OF RAINFALL INTO FRIDAY.
THE LATEST ADVISORY FROM THE NHC FOR T.D. TWO HAS IT TRACKING
SOUTH AND DISSIPATING BEFORE NEXT WEEK, BUT A WEAKENING
FRONT/LINGERING TROUGHING OVER FLORIDA SHOULD ALLOW FOR CONTINUED
UNSETTLED WET CONDITIONS THROUGH MOST OF NEXT WEEK.
CENTRAL U.S. RIDGING ALOFT WILL MAINTAIN AN AXIS OF ABOVE NORMAL
TEMPERATURES FROM THE NORTHERN PLAINS SOUTH-SOUTHEAST TO THE
MID-SOUTH, WITH PLUS 10-15F ANOMALIES FOR HIGHS POSSIBLE MOST
DAYS. INITIAL WARMTH OVER THE GREAT LAKES WILL MODERATE EARLY NEXT
WEEK AFTER A COLD FRONT PUSHES THROUGH FROM THE NORTHEAST. THE
NORTHWEST WILL BE THE OTHER FOCUS FOR VERY WARM TEMPERATURES, WITH
HIGHS 10-20F OR SO ABOVE NORMAL. EXPECT BELOW NORMAL TEMPERATURES
OVER THE NORTHEAST AND AT TIMES INTO THE MID-ATLANTIC AS UPPER
TROUGHING BECOMES ESTABLISHED. CLOUDS AND PERIODS OF RAINFALL
SHOULD KEEP HIGHS 5-10F OR SO BELOW NORMAL OVER THE SOUTHERN HALF
OF THE ROCKIES/HIGH PLAINS FOR MOST OF THE PERIOD AND THE UPPER
LOW REACHING SOUTHERN CALIFORNIA MONDAY WILL ALSO BRING A COOLING
TREND INTO THE SOUTHWESTERN U.S. NEXT WEEK.
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, EXPERIMENTAL EXCESSIVE RAINFALL
OUTLOOK, WINTER WEATHER OUTLOOK PROBABILITIES AND HEAT INDICES 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
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