Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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

000
FXUS63 KMQT 281929
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
329 PM 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 NIGHT THROUGH THURSDAY)
ISSUED AT 328 PM EDT THU AUG 28 2014

NAM SHOWS A SHORTWAVE TROUGH AFFECTING THE UPPER GREAT LAKES 00Z SAT
AND AFFECTS THE AREA FRI NIGHT. THE TROUGH AXIS PASSES THROUGH THE
AREA SAT AND IS FOLLOWED BY A SHORTWAVE RIDGE SAT NIGHT INTO SUN
WHILE ANOTHER TROUGH MOVES INTO THE NORTHERN PLAINS. NAM BRINGS IN
SOME DEEPER MOISTURE AND 850-500 MB Q-VECTOR CONVERGENCE FRI NIGHT
WHICH MOVE OUT ON SAT. WENT CATEGORICAL POPS FOR FRI NIGHT ACROSS
THE CENTRAL AND EASTERN CWA WITH LESSER POPS IN THE FAR NORTH AND
WEST. LIKELY POPS PULL OUT ON SAT WITH DIMINISHING POPS SAT NIGHT
AND DRY FOR SUN. DID NOT MAKE TOO MANY CHANGES TO THE GOING
FORECAST. DOES LOOK HUMID FOR SAT.

IN THE EXTENDED...ECMWF AND GFS SHOW A BROAD 500 MB TROUGH ACROSS
THE WESTERN HALF OF THE U.S. WITH RIDGING ACROSS THE EASTERN HALF AT
12Z MON. THERE IS A NEGATIVE TILTED SHORTWAVE AFFECTING THE UPPER
GREAT LAKES AT THAT TIME. THIS SHORTWAVE PASSES THROUGH...BUT THE
500 MB TROUGH REMAINS OVER THE AREA 12Z TUE. UPPER FLOW THEN BECOMES
MORE ZONAL ACROSS THE AREA 12Z WED INTO THU WITH A HINT OF THE 500
MB RIDGE ACROSS THE EASTERN U.S. TRYING TO BUILD BACK TOWARDS THE
AREA. WHAT THIS WILL MEAN IS A BRIEF COOL DOWN IN THE FIRST PART OF
THE PERIOD...THEN TEMPERATURES START TO WARM UP AGAIN AND WILL GET
TO NEAR NORMAL. SHOULD BE DRY FOR THE MOST PART AFTER MON NIGHT AS A
COLD FRONT EXITS THE AREA...BUT THERE COULD STILL BE INSTABILITY
SHOWERS ON TUE AND HAVE SLIGHT CHANCE POPS IN FOR THAT. WARM FRONT
APPROACHES THE AREA ON THU...SO POPS START TO RETURN THEN.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 145 PM EDT THU AUG 28 2014

VFR CONDITIONS ARE EXPECTED INTO LATE TONIGHT WITH LOW-END VFR
DIURNAL CUMULUS DISSIPATING BY 00Z. LOW PRESSURE APPROACHING FROM
THE SW WILL BRING RAIN AND QUICKLY LOWER CIGS LATE TONIGHT FOR ALL
SITES. IFR CIGS ARE EXPECTED FOR SAW AND CMX...WITH NEAR IFR
CONDITIONS FOR IWD...BY 15Z FRIDAY. GIVEN UPSLOPE ASSISTANCE WITH
SSE FLOW...CIGS AT SAW AND CMX MAY FALL BELOW ALTERNATE LANDING
MINS. AN EXTENDED PERIOD OF SUB-IFR CIGS IS THEN EXPECTED TO
CONTINUE INTO SATURDAY.
&&

.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...07
AVIATION...KLUBER
MARINE...SRF






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