Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 311607
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1207 PM EDT SUN AUG 31 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 514 AM EDT SUN AUG 31 2014

WV IMAGERY AND RUC ANALYSIS INDICATED A MID LEVEL RIDGE FROM THE
UPPER MS VALLEY THROUGH WRN LAKE SUPERIOR BTWN A DEPARTING SHRTWV
TROUGH INTO NRN LOWER MI AND AN UPSTREAM SHRTWV OVER THE WRN
DAKOTAS. ISOLATED SHOWERS ASSOCIATED WITH THE COMMA HEAD OF THE MI
SHRTWV WERE EXITING THE ERN CWA. HOWEVER...EXTENSIVE LOW LEVEL
MOISTURE/LOW CLOUDS PERSISTED OVER MUCH OF UPPER MI...EXCEPT FROM
CMX/P59 TO IWD. AT THE SFC...A RIDGE EXTENDED FROM JAMES BAY AND NRN
ONTARIO INTO WRN UPPER MI AND NW WI.

TODAY...AS THE 850-700 MB MOISTURE DEPARTS THIS MORNING AND DAYTIME
HEATING/MIXING INCREASES...EXPECT THAT THE REMAINING CLOUDS OVER THE
CNTRL AND EAST WILL THIN OUT AND GIVE WAY TO SCT CU BY AFTERNOON.
WITH SUBSIDENCE LIMITING INVERSION HEIGHTS CLOSER TO 900 MB...MAX
TEMPS MAINLY IN THE MID 70S ARE IN STORE WITH SOME LOWER READINGS
NEAR THE GREAT LAKES WHERE E OR SSE WINDS PREVAIL.

TONIGHT...AS THE DAKOTAS SHORTWAVE AND ASSOCIATED SFC TROUGH
APPROACH THE REGION SRLY FLOW AND MOISTURE ADVECTION WILL INCREASE.
AS PWAT VALUES CLIMB INTO THE 1.5-2.0 INCH RANGE FROM NW WI TO NEAR
IWD AND LARGE SCALE LIFT INCREASES WITH UPPER LEVEL DIV 700-300 MB
QVECTOR CONV AHEAD OF THE MID LEVEL TROUGH...SHRA/TSRA THAT DEVELOP
OVER MN WILL SPREAD TOWARD AND INTO THE CWA...MAINLY AFT 06Z. WITH
THE INITIAL PUSH OF 850-700 MB THETA-E ADVECTION SOME ISOLD SHRA/TSRA
MAY ALSO SPREAD INTO N CNTRL UPPER MI DURING THE EVENING...BUT
CONFIDENCE INTO CNTRL UPPER MI IS LOW WITH ONLY SLIGHT CHANCE POPS
MENTIONED. THE BEST CHANCE FOR SVR STORMS IS EXPECTED TO REMAIN WEST
OF THE CWA...CLOSER TO THE GREATER INSTABILITY. HOWEVER...WITH
MUCAPE VALUES TO AT LEAST 1K J/KG AND FAVORABLE 0-1KM/0-6KM SHEAR
TO 30/40 KNOTS...SOME STRONG STORMS WILL BE POSSIBLE WITH GUSTY
WINDS AND SMALL HAIL. THE MAIN HAZARD WITH TSRA LATE TONIGHT WILL BE
LOCALLY HEAVY RAIN WITH SOME ISOLD 1-2 INCH AMOUNTS POSSIBLE.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 433 AM EDT SUN AUG 31 2014

UPPER LEVELS FEATURE TROUGHING OVER THE CENTRAL CONUS TO BEGIN THE
PERIOD BUT THAT GIVES WAY TO SHALLOW RIDGING BY MID WEEK. SHORTWAVE
TROUGH MOVES FROM ROCKIES TO CENTRAL CANADA BY LATE THIS WEEK...WITH
WARM SW FLOW ALOFT STREAMING ACROSS THE GREAT LAKES. COLD FRONT MOVES
THROUGH AROUND FRIDAY WITH SFC RIDGE AND DRY/COOLER AIR SETTLING
OVER UPPER GREAT LAKES BY NEXT WEEKEND. CHANCES FOR SHRA/TSRA ON
LABOR DAY AS STRONG SHORTWAVE AND COLD FRONT CROSS UPPER GREAT
LAKES. THERE WILL BE ADDITIONAL CHANCES FOR SHRA AND TSRA AHEAD AND
ALONG THE LATE WEEK COLD FRONT AS WELL. EXPECT TEMPS FOR THE MOST
PART TO BE ABOVE NORMAL THROUGH THE WEEK. TEMPS PROBABLY WILL NOT
FALL BLO NORMAL UNTIL NEXT WEEKEND IN WAKE OF THE COLD FRONT PASSAGE
ON FRIDAY.

THUNDER CHANCES AND STRENGTH ON LABOR DAY AND AGAIN WEDNESDAY NIGHT
THROUGH FRIDAY LOOKS TO BE THE HIGHEST IMPACT WEATHER THIS WEEK.

LABOR DAY...INITIAL SHORTWAVE CURRENTLY DRIVING SHRA/TSRA OVER THE
DAKOTAS LIFTS OVER ONTARIO TO START THE DAY WHILE ANOTHER SHORTWAVE
CURRENTLY OVER OREGON/IDAHO TRACKS TOWARD WESTERN GREAT LAKES. MAIN
SFC LOW WILL BE NORTH OF LK SUPERIOR CLOSER TO LEADING SHORTWAVE. SFC
TROUGH WILL EXTEND SOUTH ACROSS UPPER GREAT LAKES REGION AND ON INTO
THE SOUTHERN PLAINS. H85-H5 Q-VECTOR CONVERGENCE MOSTLY IMPACTS CWA
IN THE MORNING. MOISTURE TRANSPORT AT H85-H7 IS MAXIMIZED AHEAD OF
THE FRONT IN THE MORNING AS WELL. THERE WILL BE SOME RISK FOR
STRONGER STORMS AS DURING THIS PERIOD OF FORCING/LIFT THERE IS A H85
JET UP TO 50 KTS FM THE SOUTHWEST/0-6KM SHEAR OVER 40 KTS AND 1-6KM
MUCAPES UP TO 500 J/KG. FREEZING LEVEL IS BTWN 12-13KFT WITH STORM
CORES HAVING TO REACH ABOVE 35 KFT FOR POTENTIAL OF ONE-INCH HAIL.
INSTABILITY WILL BE LIMITING FACTOR...BUT THERE MAY BE AT LEAST
ISOLATED STRONGER STORMS. BY AFTN...MLCAPES SPIKE UP WELL OVER 1000
J/KG ESPECIALLY CNTRL CWA...BUT SFC FRONT IS ON ITS WAY ACROSS CWA BY
THAT TIME AND LARGER SCALE SUBSIDENCE SHOULD BE DEVELOPING IN WAKE OF
SHORTWAVES MOVING THROUGH LATE TONIGHT INTO MONDAY MORNING. IF SFC
FRONT SLOWS UP...EVEN JUST SLIGHTLY...ISOLD STORMS MAY TRY TO DEVELOP
WITH THE INCREASING DAYTIME HEATING/INSTABILITY. RISK OF SEVERE STILL
THERE AS WELL WITH 0-6KM SHEAR 35-40 KTS. MAX TEMPS ON LABOR DAY
HIGHLY DEPEND ON EXTENT OF CLOUD COVER...BUT SEEMS THAT MANY AREAS
WILL SEE READINGS WELL INTO THE 70S. SOUTH WINDS MAY BE GUSTY OVER
EASTERN THIRD OF CWA...ESPECIALLY NEAR LK MICHIGAN SHORE.

FRONT CLEARS EASTERN CWA BY MONDAY EVENING WITH HIGH PRESSURE
SETTLING ACROSS FOR LATER MONDAY NIGHT INTO TUESDAY. ONSHORE WNW
WINDS WILL KEEP LK SUPERIOR SHORE COOLER ON TUESDAY IN THE MID-UPR
60S...BUT TEMPS SHOULD MAINLY BE IN THE LOWER 70S ELSEWHERE.

AS FLOW ALOFT BECOMES MORE ZONAL BY WEDNESDAY MAY START TO SEE
WEAKER SHORTWAVES WORK ACROSS UPR LAKES. GFS/GEM-NH AGGRESSIVE
WITH QPF ON WEDNESDAY BUT GFS SOUNDINGS INDICATE DEEPER MOISTURE IS
LACKING WITH ONLY WEAKER SHORTWAVES SHOWN. PREFER SLOWER ECMWF
SOLUTION SHOWING BETTER CHANCES OF SHRA/TSRA ARRIVING BY WEDNESDAY
NIGHT AS STRONGER SHORTWAVE ARRIVES. LAST FEW RUNS OF ECMWF ARE
SHOWING GREATER SIGNAL OF THIS OCCURRING. STRONG LOW-LEVEL MOISTURE
TRANSPORT AIMED INTO THE UPR LAKES ALONG WITH LARGE AREA OF ML
MUCAPES OVER 1000-1500 J/KG UPSTREAM WITH LIFT ENHANCED BY RIGHT
ENTRANCE REGION OF JET STREAK OVER ONTARIO/QUEBEC COULD RESULT IN AT
LEAST ISOLD STRONG ELEVATED STORMS WEDNESDAY NIGHT INTO THURSDAY
MORNING WITH ANOTHER ROUND OF STRONGER SFC BASED STORMS ALONG FRONTAL
BOUNDARY POSSIBLE LATER THURSDAY. LIMITING FACTOR FOR ADDITIONAL
STORMS LATER IN THE DAY WOULD BE NOT AS MUCH MOISTURE ALONG THE SFC
FRONT IN WAKE OF THE SHORTWAVE THAT MOVES THROUGH THURSDAY MORNING.
TEMPS AHEAD OF THE FRONT ON THURSDAY COULD GET QUITE WARM AS H85
TEMPS SURGE TOWARD +20C. WITH FULL SUNSHINE THIS WOULD SUPPORT HIGHS
INTO THE UPPER 80S IF NOT LOWER 90S. CURRENT FORECAST IS MORE TOWARD
CONSENSUS WITH UNCERTAINTY ON CLOUDS AND PRECIP CHANCES. WILL BE
SOMETHING THAT MAY NEED ADJUSTING IN LATER FORECASTS THOUGH.

THE FRONT...ALONG WITH SOME POTENTIAL FOR ADDITIONAL SHRA/TSRA...
SLIDES EAST AND SOUTH OF MOST CWA BY FRIDAY. HIGH PRESSURE MOVES
ACROSS FOR AT LEAST THE START OF NEXT WEEKEND WITH A MODEST COOLING
TREND.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1206 PM EDT SUN AUG 31 2014

EXPECT LINGERING SC IFR CIGS AT CMX AND SAW TO DISSIPATE WITH MIXING
EARLY THIS AFTERNOON. OTHERWISE...VFR CONDITIONS WILL CONTINUE UNTIL
LATE TONIGHT INTO MON MORNING AS NEXT SYSTEM AND RAIN ARRIVES BY
THEN FOR IWD AND CMX. SAW IS A DIFFERENT STORY AS THERE IS A
POTENTIAL OF AN UPSLOPE LOW CLOUD/FOG EVENT FROM LAKE MICHIGAN WITH
SOUTH WINDS AND PUT THAT SCENARIO OF LIFR/IFR CONDITIONS WITH FOG
AND LOW CLOUDS THERE TONIGHT. ON MON MORNING...RAIN WILL HAVE
STARTED AND IFR/LIFR CONDITIONS FOR ALL SITES WILL PREVAIL. LLJ SETS
UP TONIGHT OFF THE SFC AT ALL SITES AND PUT IN LLWS TO COVER IT.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 514 AM EDT SUN AUG 31 2014

WINDS WILL BE LESS THAN 20 KTS OR LESS THROUGH MOST OF THE PERIOD
EXCEPT FOR A PERIOD OF SE TO S GUSTS OF 20 TO 30 KNOTS TONIGHT AND
MONDAY MORNING. WINDS WILL THEN VEER WRLY TO 20 KNOTS MON AFTERNOON
AND MON NIGHT IN THE WAKE OF A LOW PRESSURE SYSTEM AND COLD FRONT.
WIDESPREAD FOG WILL CONTINUE THROUGH THIS MORNING AND THEN DEVELOP
AGAIN TONIGHT INTO MONDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07
MARINE...JLB







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