Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 281141
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
741 AM EDT THU AUG 28 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 424 AM EDT THU AUG 28 2014

HIGH PRESSURE IS CENTERED OVER UPPER MICHIGAN EARLY THIS
MORNING...WHICH HAS LED TO A VERY COOL LATE AUGUST MORNING FOR PARTS
OF THE AREA UNDER PARTLY CLOUDY TO MOSTLY CLEAR SKIES. 3AM
TEMPERATURES RANGE FROM 32 DEGREES AT SPINCICH LAKE TO 63 DEGREES IN
MENOMINEE. THIS DISPARITY OF TEMPERATURES IS DUE TO A COUPLE POCKETS
OF CLOUDS THAT ARE AFFECTING THE U.P. THE FIRST AREA IS OVER THE
SOUTHEAST PART OF UPPER MICHIGAN AND HAS BEEN NEARLY STATIONARY AND
SLOWLY EXPANDING OVER THE LAST COUPLE HOURS. THE SECOND AREA FORMED
OVER THE MINNESOTA ARROWHEAD AROUND MIDNIGHT AND HAS EXPANDED AS IT
SHIFTED SOUTHEAST ACROSS WESTERN LAKE SUPERIOR AND IS NOW SPREADING
INTO THE WESTERN TIER OF COUNTIES IN UPPER MICHIGAN. WILL FOLLOW A
PERSISTENCE TREND OVER THE NEXT 3-6HRS FOR THESE FEATURES...WHICH
MAKES FOR A DIFFICULT FORECAST FOR THE TEMPS AND FOG POTENTIAL DURING
THAT PERIOD. DID TRIM THE PATCHY FOG BACK THIS MORNING FROM AREAS
WHERE THE FORECAST HAD A PARTLY CLOUDY SKY. FARTHER TO THE
SOUTHWEST...AN UPPER WAVE SEEN SPINNING IN THE CENTRAL ROCKIES ON
WATER VAPOR IMAGERY WILL BE THE CONTROLLING FACTOR FOR WEATHER IN THE
U.P. FOR THE START OF THE LABOR DAY WEEKEND.

THE HIGH PRESSURE CURRENTLY OVER THE U.P. WILL SHIFT TO THE EAST
TODAY AS THE UPPER LEVEL RIDGE AXIS JUST TO THE EAST OF LAKE
WINNIPEG SHIFTS TO THE EAST AND ACROSS ONTARIO THIS AFTERNOON AND
TONIGHT. THE EXISTING CLOUDS MAKE FOR A COMPLICATED CLOUD COVER
FORECAST THIS MORNING AND HAVE TRENDED THE FORECAST TO PARTLY/MOSTLY
CLOUDY THROUGH THE FIRST COUPLE HOURS AFTER DAYBREAK. ALTHOUGH THE
CLOUDS MAY DIMINISH SOME DURING THE MORNING...THE PRESENCE OF THE
850-800MB MOISTURE WILL LEAD TO DIURNAL CLOUD DEVELOPMENT/THICKENING
BY LATE MORNING AND INTO THE AFTERNOON HOURS. IN ADDITION...WITH THE
APPROACHING WAVE THAT WILL LEAD TO INCREASING CHANCES FOR SHOWERS
AND MAYBE AN ISOLATED THUNDERSTORM TONIGHT...EXPECT HIGH CLOUDS TO
BE INCREASING LATER IN THE AFTERNOON AND CONTINUE TO INCREASE IN
THICKNESS WHILE LOWERING THROUGH THE EVENING HOURS AS THE WAVE COMES
CLOSER TO THE AREA. THUS...WILL SHOW THICKENING CLOUDS THROUGH THE
REST OF THE AFTERNOON AND HAVE SKIES CLOUDY BY MIDNIGHT. THE CLOUDS
MAY TRY TO LIMIT SOME OF THE HEATING TODAY...BUT STILL THINK HIGHS
SHOULD TOP OUT AROUND 70 DEGREES FOR MOST LOCATIONS.

AS FOR THAT WAVE MOVING TOWARDS THE AREA TONIGHT...MODELS SEEM TO
HAVE TRENDED A LITTLE SLOWER WITH THE ARRIVAL OF THE PRECIPITATION
FOR TONIGHT (MAINLY AFTER MIDNIGHT AND LIKELY TOWARDS DAYBREAK) EVEN
THOUGH SOME OF THE INITIAL WAVES START TO MOVE INTO THE AREA DURING
THE EVENING. THIS DELAY IS DUE TO THE EXISTING DRY MID LEVEL AIR
THAT WILL NEED TO BE OVERCOME DURING THE EVENING HOURS. THUS...WILL
KEEP POPS CONFINED TO THE WISCONSIN BORDER AREA TOWARDS THE LATE
EVENING AND THEN INCREASE THEM FROM SOUTHWEST TO NORTHEAST DURING
THE OVERNIGHT HOURS TO AT LEAST LIKELY POPS. MODELS VARYING
SOMEWHAT ON THE LOCATIONS OF THE BEST PRECIP...BUT THINK THE BROAD
MID LEVEL WARM AIR AND MOISTURE ADVECTION THAT LIFTS NORTHEAST
ACROSS THE AREA WITH THE SHORTWAVE WILL LEAD TO RAIN OVER MOST OF
THE CWA. DID SHOW THE HIGHEST POPS TOWARDS 12Z (LOW END DEFINITE)
OVER THE SOUTH CENTRAL U.P. WHERE THE BEST DEEP WARM AIR ADVECTION
OCCURS. PWAT VALUES AROUND 175 PERCENT OF NORMAL COULD LEAD TO BRIEF
PERIODS OF MODERATE TO HEAVY RAIN...BUT THINK THE PERSISTENT PUSH OF
THE FORCING TO THE NORTHEAST (AROUND 20KTS) SHOULD KEEP RAINFALL
AMOUNTS FROM GETTING TOO OUT OF HAND. HAVE RAINFALL AMOUNTS THROUGH
12Z AROUND 0.33-0.50IN ALONG THE WISCONSIN BORDER AND THEN TAPERING
OFF TO THE NORTHEAST. AS FOR THUNDER...THERE IS A POCKET OF STEEPER
LAPSE RATES FROM AROUND 750-600MB THAT MOVES THROUGH DURING THE
OVERNIGHT HOURS THAT COULD LEAD TO A RUMBLE OF THUNDER...BUT DON/T
EXPECT ANYTHING WIDESPREAD. THEREFORE...HAVE JUST SHOWN SLIGHT
CHANCES OF THUNDER WHERE POPS ARE ABOVE LIKELY.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 508 AM EDT THU AUG 28 2014

PROGRESSIVE FLOW WILL BE THE RULE ACROSS SRN CANADA THRU THE LONG
TERM PORTION OF THE FCST. INITIALLY...THE FLOW WILL BE LOW
AMPLITUDE...BUT IT WILL BECOME MORE AMPLIFIED EARLY NEXT WEEK AS A
MORE SUBSTANTIAL TROF DROPS INTO THE NW CONUS THIS WEEKEND AND THEN
SHIFTS E ACROSS THE NRN CONUS. DESPITE SOME AMPLIFICATION...THE
FLOW WILL REMAIN QUITE PROGRESSIVE. A WEAKER SRN BRANCH FLOW
CURRENTLY FEATURES A TROF AND WELL-DEFINED SHORTWAVE OVER WY/CO.
THIS SRN STREAM WILL FADE AWAY AHEAD OF THE MORE SIGNIFICANT NRN
STREAM TROF PUSHING ACROSS THE CONUS EARLY NEXT WEEK. ALTHOUGH THERE
WILL BE SOME FLUCTUATION...TEMPS OVERALL SHOULDN`T STRAY TOO FAR FROM
LATE AUG/EARLY SEPT NORMALS SINCE FLOW WILL BE PROGRESSIVE AND NOT
SIGNIFICANTLY AMPLIFIED. AS FOR PCPN...SRN STREAM WILL BRING PERIODS
OF WET WEATHER WITH THE POTENTIAL FOR MDT/HEAVY 2-DAY RAIN TOTALS
FRI/SAT OVER ROUGHLY THE SE HALF OF UPPER MI. WHILE SUNDAY PROVIDES
A GOOD OPPORTUNITY FOR A DRY DAY...THE EXTENDED HOLIDAY WEEKEND WILL
END ON A WET NOTE ON LABOR DAY AS A VIGOROUS COLD FRONT SWEEPS ACROSS
THE AREA. DRIER WEATHER WILL RETURN FOR TUE/WED.

BEGINNING FRI...SRN BRANCH TROF WILL SHIFT OUT OVER THE PLAINS...AND
DISTURBANCES LIFTING OUT OF THE TROF WILL TRACK ACROSS THE UPPER
LAKES. MAIN SHORTWAVE IN THE TROF WILL THEN LIFT ACROSS THE UPPER
LAKES SAT WITH SRN BRANCH FLOW FADING AWAY THEREAFTER. STRONGEST
SURGE OF MOISTURE TRANSPORT ACROSS THE FCST AREA OCCURS FRI WITH A
SECONDARY SURGE FRI NIGHT/EARLY SAT...MAINLY AFFECTING THE SE HALF
IN ASSOCIATION WITH MAIN SHORTWAVE LIFTING THRU THE UPPER LAKES.
RIGHT ENTRANCE OF UPPER JET WILL ASSIST PCPN FRI...ESPECIALLY OVER
THE SE HALF OF THE FCST AREA. WITH PRECIPITABLE WATER RUNNING
150-200PCT OF NORMAL...THERE IS THE POTENTIAL FOR MDT/HVY RAINFALL
TOTALS FRI/SAT (1-3 INCHES NOT OUT OF THE QUESTION) WHERE SHRA ARE
MOST PERSISTENT OVER THE SCNTRL AND ERN FCST AREA. NOT MUCH
INSTABILITY IS PRESENT. SO...NOT EXPECTING ANY SVR STORMS.
OVERALL...LIKELY TO CATEGORICAL POPS WILL BE UTILIZED OVER ALL BUT
THE FAR W FRI THRU SAT MORNING.

DRYING OCCURS LATER SAT INTO SUN IN THE WAKE OF SRN STREAM WAVE.
PASSAGE OF NRN STREAM SHORTWAVE TROF ACROSS NRN ONTARIO FRI NIGHT
WILL ALSO AID DRYING AS THE FOLLOWING RIDGE HELPS TO PUSH DRIER AIR
INTO UPPER MI. WILL BEGIN TO TREND POPS DOWN FROM NW TO SE SAT
AFTN/EVENING WITH DRY WX ACROSS THE AREA BY LATE SAT NIGHT. WITH THE
RAINFALL FRI/SAT AND A WEAK SFC HIGH PRES RIDGE SETTLING OVER
W/CNTRL UPPER MI SAT NIGHT AS CLOUDS BEGIN TO SCATTER OUT...
RADIATIONAL FOG DEVELOPMENT APPEARS TO BE A GOOD BET...LINGERING
INTO MID OR EVEN LATE MORNING SUN. SUN WILL OTHERWISE BE A DRY DAY
UNDER GENERALLY A MOSTLY SUNNY SKY.

AS THE MORE SUBSTANTIAL TROF OVER THE NW CONUS SHIFTS EASTWARD EARLY
NEXT WEEK...A VIGOROUS COLD FRONT WILL SWEEP E ACROSS THE GREAT
LAKES...BRINGING A GOOD POTENTIAL FOR SHRA/TSRA. THE TYPICALLY FAST
BIASED GFS HAS NOT SHOWN A SIGNIFICANT TREND...BUT THE GEM/ECMWF
HAVE SHOWN SOLID FASTER TRENDS WHICH BRING THEM UP TO THE GFS
TIMING. FOR INSTANCE...TODAYS 00Z ECMWF IS 24HRS FASTER WITH FROPA
ACROSS THE AREA COMPARED TO THE 00Z/26AUG RUN. FASTER TRENDS AND
CURRENT GOOD AGREEMENT AMONG GFS/ECMWF/GEM POINT TOWARD A WET LABOR
DAY AS VIGOROUS COLD FRONT SWEEPS ACROSS UPPER MI. AT THIS POINT...
LIKELY POPS FOR SHRA/TSTMS APPEAR REASONABLE.

DRIER WEATHER SHOULD FOLLOW FOR TUE/WED...BUT THERE ARE HINTS OF
ANOTHER QUICK MOVING SHORTWAVE TROF ARRIVING TUE...WHICH MAY SPARK
SOME ISOLD -SHRA. GIVEN THE QUICK ARRIVAL AND LACK OF MOISTURE
RETURN BEHIND MON FROPA...A MENTION OF PCPN DOESN`T APPEAR WARRANTED
ATTM FOR TUE.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 740 AM EDT THU AUG 28 2014

HIGH PRESSURE WILL DEPART THE AREA TODAY...WHICH WILL LEAD TO RAIN
MOVING INTO THE TAF SITES LATE TONIGHT INTO FRIDAY MORNING. BEFORE
THAT OCCURS...EXPECT DIURNAL CLOUD DEVELOPMENT TODAY AT THE THREE
TAF SITES BUT CONDITIONS SHOULD REMAIN VFR.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 424 AM EDT THU AUG 28 2014

HIGH PRESSURE OVER UPPER MICHIGAN WILL SHIFT TO THE EAST TODAY
WHILE A COUPLE WEAK TROUGHS MOVE NORTHEAST THROUGH THE UPPER GREAT
LAKES REGION TONIGHT THROUGH SATURDAY. THE WEAK PRESSURE GRADIENT
ASSOCIATED WITH THESE FEATURES WILL KEEP WINDS BELOW 20KTS THROUGH
THE WEEKEND...BUT A STRONGER TROUGH LIFTING NORTHEAST ACROSS THE
AREA ON MONDAY WILL LIKELY LEAD TO SOUTHERLY WINDS TO 25KTS SUNDAY
NIGHT INTO MONDAY. RAINFALL EXPECTED LATE TONIGHT THROUGH SATURDAY
WILL BRING THE POTENTIAL FOR FOG TO DEVELOP OVER LAKE
SUPERIOR...ESPECIALLY OVER THE NORTHEAST...AND CONTINUE INTO SUNDAY
MORNING.
&&

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

$$

SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...SRF
MARINE...SRF






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