Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 311150
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
750 AM EDT THU JUL 31 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 439 AM EDT THU JUL 31 2014

AN UPPER LOW CONTINUES TO SPIN NEAR JAMES BAY AND WILL REMAIN IN
PLACE OVER THE NEXT 24 HOURS. THERE IS ABUNDANT MOISTURE SEEN ON WV
IMAGERY ON THE WEST SIDE OF THE UPPER LEVEL LOW STRETCHING FROM
EASTERN UPPER MICHIGAN NORTH THROUGH ONTARIO AND OVER HUDSON BAY.
THIS IS LEADING TO SCATTERED/BROKEN MID CLOUDS OVER THE NORTHEAST
HALF OF THE CWA EARLY THIS MORNING...AND EVEN A FEW ISOLATED
SHOWERS. EXPECT THESE CLOUDS TO CONTINUE TO STREAM TO THE SOUTHEAST
EARLY THIS MORNING AS THEY WRAP AROUND THE UPPER LOW. THE SHOWERS
SHOULD FOLLOW SUIT AND WILL LIKELY BRUSH AREAS EAST OF A LINE FROM
GRAND MARAIS TO ENGADINE THROUGH A COUPLE HOURS AFTER SUNRISE. FOR
THE SOUTHWEST HALF OF THE AREA...SKIES HAVE BEEN PARTLY CLOUDY TO
MOSTLY CLEAR...WHICH HAS LED TO PATCHY RADIATIONAL FOG OVER PORTIONS
OF THAT AREA. THIS FOG MAY BE LOCALLY DENSE IN LOW LYING AREAS...BUT
LATEST WEBCAMS HAVEN/T INDICATED ANYTHING AS THICK/WIDESPREAD AS
YESTERDAY MORNING SO WILL HOLD OFF ON AN SPS FOR NOW. WITH CLOUD
THICKNESS VALUES LOWER THAN YESTERDAY (AROUND 500FT ON THE
GOES-R CLOUD THICKNESS DATA)...EXPECT THIS FOG TO BURN OFF WITHIN AN
HOUR OR TWO AFTER SUNRISE.

THE WEAK SURFACE LOW NEAR JAMES BAY WILL REMAIN NEARLY STATIONARY
TODAY AND KEEP A WEAK SURFACE TROUGH OVER THE AREA. EXPECT THE
CLOUDS OVER THE NORTHEAST HALF OF THE CWA TO DIMINISH SOME THIS
MORNING WHILE THE SOUTHWEST HAS A MOSTLY SUNNY START TO THE DAY.
FLOW ALOFT BECOMES MORE NORTHWESTERLY MORE NORTHWESTERLY
THROUGH THE DAY (ASSOCIATED WITH A WEAK SHORTWAVE MOVING
THROUGH)...HELPING SHIFT THE MID CLOUDS A LITTLE FARTHER TO THE EAST
AS THEY ROTATE AROUND THE UPPER LOW. THUS...THINK DEEP MOISTURE WILL
BE LIMITED TODAY. MODELS CONTINUE TO SHOW ENOUGH 850-700MB MOISTURE
FOR DIURNAL CUMULUS DEVELOPMENT THIS AFTERNOON...GENERALLY SOUTHEAST
OF A LINE FROM ISHPEMING TO IRON RIVER. WILL CONTINUE TO SHOW THAT
AREA BECOMING PARTLY CLOUDY THIS AFTERNOON...WHILE AREAS FARTHER TO
THE WEST SHOULD REMAIN MOSTLY SUNNY. WITH DIURNAL CLOUD DEVELOPMENT
AND EXPECTED LAKE BREEZE OFF LAKE MICHIGAN...DO BELIEVE THERE IS A
SLIGHT CHANCE OF SEEING SOME SHOWERS DEVELOPING ON THAT AREA OF
CONVERGENCE. HAVE FOLLOWED THE SIMILAR IDEA TO THE PREVIOUS SHIFT
AND HAVE THE SHOWERS SOUTHEAST OF A LINE FROM IRON MOUNTAIN...TO
KSAW...TO NEWBERRY. MUCAPE VARIES IN THE MODELS BETWEEN 150-1000
J/KG OVER THE SOUTH CENTRAL THIS AFTERNOON...BUT MLCAPE VALUES ARE
PROBABLY A LITTLE BETTER RESPRESENTATION AND LARGELY BETWEEN 150-450
J/KG OVER DELTA/MENOMINEE COUNTIES. WILL SHOW SLIGHT CHANCE OF
THUNDER ALONG THAT INSTABILITY AXIS AND SHOWERS ELSEWHERE ALONG THE
LAKE BREEZE CONVERGENCE. HIGHS TODAY WILL BE A TOUCH WARMER THAN
YESTERDAY (LOW TO MID 70S IN MOST LOCATIONS).

WITH MID LEVEL MOISTURE STILL ROTATING AROUND THE UPPER LOW
TONIGHT...IT WILL TRY TO BRUSH THE FAR NORTHEAST CWA (MAINLY OVER
NORTHEASTERN LAKE SUPERIOR) BUT SHOULDN/T HAVE MUCH AFFECT ON THE
U.P. THUS...EXPECT MOSTLY CLEAR SKIES AND LIGHT WINDS OVER MUCH OF
THE AREA. WILL CONTINUE TO SHOW PATCHY FOG OVER THE SOUTHEAST NEAR
LAKE MICHIGAN...WHERE THE POTENTIAL FOR SOME ADDITIONAL MOISTENING
FROM AFTERNOON SHOWERS EXIST. LOWS TONIGHT WILL BE IN THE MID 40S
TO LOWER 50S.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 426 AM EDT THU JUL 31 2014

DECENT AGREEMENT THAT UPPER LOW CENTERED VCNTY OF JAMES BAY
DEAMPLIFIES BY THIS WEEKEND. OTHER THAN ON SATURDAY THOUGH...TROUGHING
PERSISTS FM WESTERN CANADA ACROSS THE GREAT LAKES THROUGH MOST OF
NEXT WEEK. MEDIUM RANGE MODELS CONTINUE TO POINT TOWARD A COUPLE
PERIODS OF SHRA/TSRA. THE FIRST IS ON FRIDAY AFTN WITH THE SECOND
COMING IN LATER SUNDAY.

THE CHANCES ON FRIDAY ARE MAINLY INLAND OVER THE WEST HALF OF UPR
MICHIGAN. NAM AND ECMWF INDICATE SHORTWAVE/Q-VECTOR CONVERGENCE AND
POCKET OF H7-H5 MOISTURE CROSSES IN THE AFTN OVER NORTHERN WI AND
WESTERN UPR MICHIGAN WHILE GFS AND GEM ARE FARTHER SOUTHWEST WITH
THIS FORCING. TEMPS RISING WELL INTO THE 70S RESULTS IN MLCAPES INTO
INTERIOR WEST CWA PUSHING TOWARD 500J/KG...BUT GREATER INSTABILITY
SHOULD BE RESTRICTED BY AFTN DWPTS ONLY INTO THE UPR 40S/LWR 50S. NAM
DWPNTS INTO THE LOWER 60S SEEM WAY OVERDONE AND RESULT IN MLCAPES
WELL OVR 1000 J/KG. CONTINUED TO HIGHLIGHT HIGHER CHANCE POPS OVER
THE CNTRL CWA WHERE BEST INSTABILITY MATCHES UP WITH LAKE BREEZE
CONVERGENCE. ANY SHOWERS AND STORMS WILL MOVE TO THE ESE AT 20-25 MPH
BASED ON H7 WINDS. LOWER INSTABILITY AND WEAKISH SHEAR UP TO 20 KTS
SHOULD RESULT IN HEAVY DOWNPOURS AS MAIN HAZARD FM ANY STORMS.
YET...SINCE WBZERO HEIGHTS ARE ONLY IN THE 8-9KFT AGL RANGE ANY ISOLD
STRONGER STORMS COULD CERTAINLY PRODUCE PEA SIZED HAIL. LACK OF
STRONGER LARGER SCALE FORCING WILL ALLOW ANY SHOWERS OR STORMS TO END
EARLY ON FRIDAY NIGHT WITH LOSS OF HEATING.

HIGH PRESSURE RIDGE SETTLES ACROSS FOR LATE FRIDAY INTO SATURDAY.
PWATS FALL TOWARD 50 PCT OF NORMAL...INDICATING GOOD RADIATIONAL
COOLING FRIDAY NIGHT WITH LIGHT WINDS. MINS SHOULD FALL INTO LOW TO
MID 40S. SHOULD SEE PATCHY TO AREAS OF FOG IN THE INLAND AREAS.
THIKN THE NAM IS UP TO ITS TRICKS AGAIN ON SATURDAY...BY SHOWING TOO
MOIST OF LOW-LEVELS RESULTING IN TOO HIGH OF MLCAPES. TOOK OUT ANY
MENTION OF SHRA ON SATURDAY EVEN WITH SOME LAKE BREEZE CONVERGENCE.
INLAND AREAS AROUND 80 BASED ON MIXING TO H85 AND ONLY SCT CU.

ATTN LATER SATURDAY NIGHT INTO SUNDAY IS ON STRONGER SHORTWAVE
DROPPING THROUGH IN WNW FLOW ALOFT AS LARGER SCALE TROUGH DEEPENS
YET AGAIN. THE SHORTWAVE AND ASSOCIATED SFC COLD FRONT WORKS ACROSS
UPPER LAKES LATER SUNDAY INTO SUNDAY NIGHT AND IT SEEMS THAT MODELS
ARE MORE LOCKED IN ON MOST SHRA/TSRA OCCURRING DURING THIS TIME.
DRYING TREND THEN DEVELOPS LATE SUNDAY NIGHT INTO MONDAY. EXPECT
MLCAPES TO BE MORE TOWARD 1000J/KG DURING PEAK HEATING ON SUNDAY AS
DWPNTS SURGE UP TO AROUND 60 OVER NORTHERN WI AND PERHAPS WEST CWA
CLOSER TO WI BORDER. DEEP LAYER SHEAR TOWARD 30 KTS ALONG WITH THE
FORECAST INSTABILITY WOULD SUPPORT RISK OF STRONGER STORMS. LOW-LEVEL
CONVERGENCE ALONG THE FRONT MAY BE HELPED ALONG BY LAKE BREEZES AS
WELL. AGREE WITH DAYSHIFT FM WEDNESDAY... THAT COULD SEE SOME STRONGER
STORMS SUNDAY AFTN AND EVENING. BASED ON LACK OF OVERWHELMING EVIDENCE
THOUGH...WILL NOT HIGHLIGHT THIS TIME FRAME IN THE HAZARDOUS WEATHER
OUTLOOK JUST QUITE YET.

FRONT SHOULD BE SOUTH AND EAST OF UPR MICHIGAN TO START THE DAY ON
MONDAY SO EXPECT MINIMAL CHANCES OF SHRA/TSRA MONDAY INTO TUESDAY AS
HIGH PRESSURE BEHIND THE TROUGH EXPANDS ACROSS THE REGION. AFTER
TEMPS NEAR NORMAL THIS WEEKEND...TEMPS EARLY NEXT WEEK WILL RETURN
TO BLO NORMAL VALUES YET AGAIN. MOST NOTABLE COOLING WILL BE OVER
THE NORTHERN U.P. WITH GRADIENT NORTH FLOW OFF LK SUPERIOR.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 750 AM EDT THU JUL 31 2014

VFR CONDITIONS ARE EXPECTED THROUGH MUCH OF THE THE PERIOD.
INITIALLY...SOME LOW CLOUDS AND FOG DEVELOPED JUST TO THE WEST OF
THE KEWEENAW PENINSULA AND THE WESTERLY WINDS HAVE SHIFTED IT INTO
KCMX. THERE ARE SOME HINTS OF IT TRYING TO BREAK UP ALREADY...BUT
HAVE INCLUDED LIFR CEILINGS FOR THE FIRST HOUR OR SO.
OTHERWISE...THE MAIN ITEM OF IMPORTANCE IS THE EXPECTATION OF
DIURNAL CLOUD DEVELOPMENT AT KSAW THIS AFTERNOON. THERE MAY BE A FEW
SHOWERS THAT DEVELOP ALONG THE LAKE BREEZE IN MARQUETTE COUNTY...BUT
AT THIS TIME EXPECT THEM TO STAY MAINLY TO THE SOUTHEAST OF KSAW.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 439 AM EDT THU JUL 31 2014

WITH A WEAK PRESSURE GRADIENT TYPICAL OF SUMMER DOMINATING THIS
FORECAST PERIOD...EXPECT WINDS UNDER 15 KTS THROUGH MONDAY.

THERE IS THE POTENTIAL FOR PATCHY FOG OVER THE NEXT SEVERAL
DAYS FOR PORTIONS OF LAKE SUPERIOR...BUT DON/T EXPECT ANY
WIDESPREAD DENSE FOG AT THIS TIME.
&&

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

$$

SHORT TERM...SRF
LONG TERM...JLA
AVIATION...SRF
MARINE...SRF






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