130
FXUS02 KWBC 101859
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
259 PM EDT TUE JUN 10 2025
VALID 12Z FRI JUN 13 2025 - 12Z TUE JUN 17 2025
...HEAVY RAIN AND FLASH FLOOD THREAT FROM THE SOUTH-CENTRAL U.S.
THROUGH THE OHIO VALLEY/NORTHEAST FRIDAY INTO THE WEEKEND...
..GENERAL OVERVIEW
A SLOW MOVING SHORTWAVE TROUGH SETTLING OVER THE SOUTH-CENTRAL
U.S. WILL CONTINUE TO FOCUS HEAVY RAINFALL AND POTENTIAL FLASH
FLOODING THROUGH AT LEAST FRIDAY, ESPECIALLY ACROSS PORTIONS OF
TEXAS, OKLAHOMA, AND INTO THE LOWER MISSISSIPPI VALLEY. NORTHERN
STREAM ENERGY MAY MEANWHILE SUPPORT SOME MODERATE TO HEAVY
RAINFALL FOCUS ACROSS PORTIONS OF WISCONSIN AND MICHIGAN, WITH
RAINFALL INCREASING IN COVERAGE BY NEXT WEEKEND ACROSS THE OHIO
VALLEY INTO THE EAST AHEAD OF NORTHERN AND SOUTHERN STREAM ENERGY
TRANSLATION AND INTERACTION. UPSTREAM, THE BULK OF UPPER TROUGH
ENERGY WILL BE SLOW TO WORK INLAND FROM THE WEST COAST, BUT WILL
BE PERIODICALLY RENEWED BY SHORTWAVES ROUNDING THE BASE OF A LARGER
UPPER LOW, WITH ABOVE NORMAL TEMPERATURES EXPECTED TO PREVAIL FOR
INTERIOR PORTIONS OF THE WEST UNDERNEATH UPPER RIDGING. HEAT WILL
IN PARTICULAR FOCUS OVER THE SOUTHWEST THIS WEEKEND AND NEXT WEEK.
..GUIDANCE/PREDICTABILITY ASSESSMENT
GUIDANCE REMAINS IN REASONABLY GOOD AGREEMENT WITH MOST OF THE
SYNOPTIC SCALE FEATURES AND OFFERS GOOD PATTERN PREDICTABILITY.
ONE OF THE MORE NOTABLE DIFFERENCES IS WITH THE UKMET SHOWING A
FASTER AND STRONGER TROUGH AND SURFACE LOW CROSSING THE OHIO VALLEY
AND THEN THE NORTHEAST THROUGH SATURDAY. PREFER A LESS PROGRESSIVE
SOLUTION GIVEN AMPLIFIED FLOW TRENDS. THE WPC MEDIUM RANGE PRODUCT
SUITE WAS MAINLY DERIVED FROM A BLEND OF GFS/ECMWF/CMC MODEL AND
ENSEMBLE MEAN SOLUTIONS ALONG WITH THE NATIONAL BLEND OF MODELS AND
WPC CONTINUITY THROUGH MEDIUM RANGE TIME SCALES. THE BLENDING
PROCESS TENDS TO SMOOTH SYSTEM DETAIL CONSISTENT WITH FEATURE
PROBABILITY, BUT NEEDED TO APPLY MANUAL ADJUSTMENTS TO ENSURE
SUFFICIENT QPF IN A WET FLOW PATTERN ON TAP WITHIN THE
AFOREMENTIONED AND DECENTLY ESTABLISHED MOISTURE/FRONTAL CHANNEL.
..WEATHER/HAZARDS HIGHLIGHTS
AN UNSETTLED WEATHER PATTERN IS EXPECTED TO BE IN PLACE ACROSS A
LARGE PORTION OF THE CENTRAL U.S. TO CLOSE OUT THE WORK WEEK.
ADDITIONAL HEAVY RAINFALL IS LIKELY ACROSS THE ARKLATEX REGION
GOING INTO THE NEW DAY 4 PERIOD FRIDAY WITH A SOUTHERN STREAM
SHORTWAVE POSITIONED OVER TEXAS. MAINTAINED THE INHERITED SLIGHT
RISK AREA FOR FRIDAY, WHERE THE POTENTIAL EXISTS FOR A FAST MULTIPLE
INCHES OF RAINFALL FROM THUNDERSTORM AND POTENTIAL MCS ACTIVITY,
AND THIS WOULD BE FALLING ATOP SOILS THAT WILL PROBABLY BE
SATURATED OWING TO RAINFALL IN THE DAYS LEADING UP TO THIS. THERE
SHOULD ALSO BE AT LEAST SCATTERED SHOWERS AND STORMS FROM THE
WESTERN GULF COAST AND EXTENDING NORTHWARD ACROSS THE MID-SOUTH,
BUT ENSEMBLE SIGNAL IS NOT VERY STRONG FOR ANY PARTICULAR PLACE IN
THE BROAD AREA, SO SHRANK THE MARGINAL RISK AREA ACCORDINGLY.
FARTHER TO THE NORTH ACROSS THE UPPER MIDWEST AND GREAT LAKES, A
WAVE OF LOW PRESSURE ALONG A QUASI-STATIONARY BOUNDARY MAY FUEL THE
DEVELOPMENT OF SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
FROM WISCONSIN TO LOWER MICHIGAN WHERE A DAY 4/FRIDAY MARGINAL RISK
AREA REMAINS IN PLACE. GOING INTO DAY 5/SATURDAY, A BROAD MARGINAL
RISK AREA IS PLANNED FROM THE WEST-CENTRAL GULF COAST TO THE
CATSKILLS OF NEW YORK TO INCLUDE SOME OF THE LOWER FFG VALUES AND
FAVORED TERRAIN. THE CURRENT GUIDANCE SIGNAL REMAIS MIXED IN
GUIDANCE FOR FIRM LOCATIONS THAT LIMITS ISSUANCE OF ANY SLIGHT RISK
AREAS THAT WILL NEED TO BE MONITORRED CLOSER TO OCCURANCE.
TEMPERATURES WILL CONTINUE TO BE QUITE WARM ACROSS MUCH OF THE
INTERMOUNTAIN WEST FOR THE ENTIRE FORECAST PERIOD AS THIS REGION
WILL BE UNDER THE INFLUENCE OF AN UPPER RIDGE, ALTHOUGH A SLOW
MOVING COLD FRONT FROM THE PACIFIC WILL KEEP READINGS CLOSER TO
CLIMATOLOGY FROM THE PACIFIC NORTHWEST TO WESTERN NEVADA/NORTHERN
CALIFORNIA. HEAT WILL ALSO BE BUILDING ACROSS THE DESERT SOUTHWEST
WITH HIGHS MAKING A RUN AT 110 DEGREES FOR THE LOWER ELEVATIONS OF
SOUTHERN ARIZONA AND SOUTHEAST CALIFORNIA, WITH HEAT RISK LIKELY
REACHING THE MAJOR CATEGORY BY SUNDAY INTO MONDAY, WITH ADDITIONAL
THREAT EXTENDING WELL INTO NEXT WEEK. MEANWHILE, SLIGHTLY BELOW
AVERAGE TEMPERATURES ARE LIKELY FROM THE UPPER MIDWEST TO THE GREAT
LAKES AND NORTHERN NEW ENGLAND GOING INTO THE WEEKEND AS THIS
REGION WILL BE NORTH OF THE MAIN FRONTAL BOUNDARY.
SCHICHTEL/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 (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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