Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS63 KDTX 031132 AFDDTX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 732 AM EDT THU SEP 3 2015 .AVIATION... EXTREMELY MOIST AND UNSTABLE ENVIRONMENT TODAY WILL PROVIDE A FAVORABLE ENVIRONMENT FOR SHOWER AND THUNDERSTORM DEVELOPMENT AREAWIDE. WHILE THERE REMAINS SOME UNCERTAINTY AS TO POTENTIAL COVERAGE...CONFIDENCE IS HIGH ENOUGH TO INCLUDE A SPECIFIC MENTION TO HIGHLIGHT THE MOST LIKELY PERIOD FOR THUNDERSTORMS. OUTSIDE OF THUNDERSTORMS...EXPANDING COVERAGE OF DIURNAL VFR CU CENTERED ON THE AFTERNOON/EVENING PERIOD. THE MOIST LOW LEVEL CONDITIONS AND PROSPECTS FOR WET GROUND WITH RECENT RAINFALL WILL BRING A GREATER POTENTIAL FOR FOG DEVELOPMENT TONIGHT. POSSIBILITY EXISTS FOR ONE OR MORE TERMINALS TO DROP INTO LIFR DURING THE EARLY MORNING PERIOD...CONFIDENCE TOO LOW YET TO INCLUDE BUT WILL HIGHLIGHT WITH IFR VSBY RESTRICTIONS. FOR DTW...GREATEST POTENTIAL FOR THUNDERSTORMS CENTERED WITHIN THE 18Z-00Z WINDOW...ALTHOUGH A LOWER PROBABILITY WILL EXIST RIGHT THROUGH THURSDAY NIGHT. //DTW THRESHOLD PROBABILITIES... * LOW FOR CIG AOB 5KFT THIS AFTERNOON AND EVENING * MEDIUM FOR THUNDERSTORMS THIS AFTERNOON AND EVENING && .PREV DISCUSSION...ISSUED 333 AM EDT THU SEP 3 2015 SHORT TERM...TODAY AND TONIGHT ATTENTION OVER THE NEXT 24 TO 36 HOURS CENTERS ON THE INBOUND SLOWLY MOVING MID LEVEL WAVE CURRENTLY CENTERED ACROSS THE LAKE MICHIGAN CORRIDOR. LITTLE VARIATION IN THE UNDERLYING LOW LEVEL THERMODYNAMIC PROFILE HEADING INTO TODAY...WITH SE MICHIGAN FIRMLY ENTRENCHED WITHIN A MOISTURE RICH LOW LEVEL ENVIRONMENT /LOWER 70S DEWPOINTS/. AS NOTED YESTERDAY...THIS WILL AGAIN TRANSLATE INTO SUBSTANTIAL LOW LEVEL INSTABILITY (2500+ J/KG SBCAPE) WITHIN A VERY STEEP LAPSE RATE ENVIRONMENT. INCREASING DPVA AND AN ACCOMPANYING POCKET OF COOLER MID LEVEL TEMPERATURES WILL CONTRIBUTE AN ADDITIONAL COMPONENT OF DESTABILIZATION AND MORE FOCUSED ASCENT FOR TODAY. THIS ENVIRONMENT SEEMS CONDUCIVE FOR A MORE SIZABLE EXPANSION IN CONVECTIVE COVERAGE LOCALLY...AND WORTHY OF A NUDGE UPWARD IN POPS...PARTICULARLY FOR THE AFTERNOON/EVENING PERIODS. THE HIGH MOISTURE CONTENT AND CORRESPONDING POTENTIAL FOR SIGNIFICANT PRECIPITATION LOADING WITHIN THE DEEPEST CONVECTIVE CELLS WILL AGAIN PRESENT THE POTENTIAL FOR STRONGER WIND GUSTS...WITH AT LEAST AN OUTSIDE POSSIBILITY THAT AN ISOLATED STORM OR TWO CAN GENERATE A PEAK GUST NEARING SEVERE LIMITS. SOLID HEAVY RAINFALL THREAT GIVEN LIKELY LIMITED STORM MOTION WITHIN THIS HIGH CAPE ENVIRONMENT. HIGHS TODAY A TOUCH LOWER WITH THE ENSUING EXPANSION IN CONVECTION/CLOUD COVER LIKELY UNDERCUTTING THE HEATING POTENTIAL SLIGHTLY. READINGS TOPPING OUT IN THE LOWER AND MIDDLE 80S...HEAT INDICES APPROACHING 90. GRADUAL COOLING VIA DIABATIC PROCESSES AND ANY OUTFLOW WILL FAVOR A DIMINISHING TREND TO EXISTING CONVECTIVE ACTIVITY BY EARLY TONIGHT. HOWEVER THE UNDERLYING ENVIRONMENT WILL STILL REMAIN FAVORABLE FOR ADDITIONAL ISOLATED-SCATTERED DEVELOPMENT THROUGHOUT THE NIGHT. INCREASING POTENTIAL FOR FOG OVERNIGHT...MOIST NEAR SURFACE ENVIRONMENT AUGMENTED BY THE RAINFALL AND WEAK GRADIENT. A CORRIDOR OF DENSE FOG FOR THE EARLY MORNING COMMUTE NOT OUT OF THE QUESTION. LONG TERM... MULTIPLE UPPER WAVES UPSTREAM OVER UPPER MISSISSIPPI RIVER VALLEY THIS MORNING...WHICH WILL CONSOLIDATE OVER THE WESTERN/CENTRAL GREAT LAKES TONIGHT INTO FRIDAY...BUT THE EXACT POSITION OF THE DEVELOPED MID LEVEL CIRCULATION/500 MB LOW IS QUESTION...AS 00Z NAM/GFS ARE INDICATING A FARTHER SOUTH/WEST SOLUTION...NEAR CHICAGO...WHILE EURO/CANADIAN REMAIN STEADFAST WITH 500 MB LOW FARTHER NORTH/EAST OVER NORTHERN LOWER MICHIGAN. EITHER WAY...CHANCE POPS STILL SEEM WARRANTED...EVEN WITH THE STRENGTHENING HIGH PRESSURE OVER EASTERN CANADA (1025 MB)...AS THE LOW LEVEL SOUTHEAST/EAST FLOW WILL INCREASE A BIT...BUT THERE ACTUALLY LOOKS TO BE MODEST MOISTURE ADVECTION FROM WESTERN PA/LAKE ERIE. MLCAPES PROGGED TO INCREASE INTO THE 500 TO 1500 J/KG RANGE DURING FRIDAY...PER 00Z EURO. STILL LINGERING UPPER LEVEL TROUGHINESS ON SATURDAY WITH MLCAPES RISING INTO THE 1000-2000 J/KG RANGE TO SUPPORT LOW CHANCE POPS. UPPER LEVEL RIDGE BUILDING OUT AHEAD OF STRONG GREAT BASIN 500 MB LOW ON SATURDAY SHOULD EXERT A BIGGER INFLUENCE FOR THE SECOND HALF OF THE WEEKEND...ALLOWING FOR TEMPERATURES TO HEAT UP ONCE AGAIN...WITH 90 DEGREES LIKELY ON SUNDAY...AS SOUTH-SOUTHWEST FLOW INCREASES OUT AHEAD OF NEXT COLD FRONT...WITH 850 MB TEMPS PROGGED TO BE IN THE 18-19 C RANGE. UPPER LEVEL RIDGE AXIS ARRIVING SUNDAY AFTERNOON IS EXPECTED TO PROVIDE ENOUGH MID LEVEL WARMING/SUBSIDENT BACKDROP TO SQUELCH POTENTIAL CONVECTION. THE SAME CAN NOT BE SAID FOR EARLY NEXT WEAK AS SOLID HEIGHT FALLS/MOISTURE PLUME/AXIS (PW VALUES OF 2 INCHES) AND COLD FRONT TRACKS THROUGH THE GREAT LAKES REGION. MARINE... STRENGTHENING HIGH PRESSURE OVER EASTERN CANADA WILL PROMOTE LIGHT EASTERLY FLOW AS WE HEAD INTO FRIDAY. UPPER LEVEL DISTURBANCE WILL RESULT IN SCATTERED SHOWERS AND THUNDERSTORMS THROUGH FRIDAY...WITH A LOW CHANCE ON SATURDAY. WINDS WILL SHIFT TO THE SOUTH OVER THE WEEKEND...BUT REMAIN LIGHT...AS VERY WARM AIR STREAMS INTO THE REGION. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....MR SHORT TERM...MR LONG TERM....SF MARINE.......SF YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.