Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 030813
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
413 AM EDT MON AUG 3 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 325 AM EDT MON AUG 3 2015

UPPER AIR PATTERN CONSISTS OF A 500 MB RIDGE OVER THE ROCKIES AND A
DEEP TROUGH OVER THE EASTERN HALF OF THE U.S. AND ACROSS THE GREAT
LAKES REGION THIS MORNING. UPPER FLOW CONTINUES TO BE FROM THE NW
AND WILL CONTINUE THAT WAY THIS FORECAST PERIOD. EMBEDDED IN THE NW
FLOW ALOFT IN THE TROUGH ARE A FEW SHORTWAVES WHICH WILL BE MOVING
THROUGH THE UPPER GREAT LAKES AND CAUSE A POSSIBILITY OF SOME
SHOWERS FOR THIS FORECAST PERIOD.

NAM HAS SOME WEAK 850-500 MB Q-VECTOR CONVERGENCE TODAY ALONG WITH
SOME MOISTURE AROUND AND BOTH MOVE OUT TONIGHT. WITH SOME MOISTURE
AROUND AND UPPER TROUGHING AS WELL...IT IS HARD TO RULE OUT SOME
SPRINKLES OR LIGHT SHOWERS AND KEPT THE SLIGHT CHANCE TO LOW CHANCE
POPS IN THE FORECAST THROUGH THIS FORECAST PERIOD AND KEPT THEM IN.
THE HIGHEST POPS WILL BE WITH THE HEATING OF THE DAY IN THE
AFTERNOON AND EARLY EVENING. DID NOT MAKE TOO MANY CHANGES TO THE
GOING FORECAST FOR TEMPERATURES.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 412 AM EDT MON AUG 3 2015

A PERIOD OF BELOW NORMAL TEMPS IS STILL IN STORE AS GREAT LAKES AND
NORTHEAST CONUS WILL BE DIRECTLY INFLUENCED BY DEEP TROUGHING
CENTERED OVER EASTERN CANADA FOR MOST OF THE WEEK. HIGH TEMPERATURES
EARLY THIS WEEK WILL BE OVER 10F BELOW NORMAL IN SOME AREAS AND WILL
BE MORE TYPICAL OF EARLY SEPTEMBER THAN EARLY AUGUST. RAIN CHANCES
WILL BE ON THE LOWER SIDE IN THIS PATTERN. SOME SHOWERS ARE POSSIBLE
ON TUESDAY WITH THERMAL TROUGH AND WEAKLY CYCLONIC LOW-LEVEL FLOW IN
PLACE. LARGE SCALE BECOMES INCREASINGLY UNFAVORABLE FOR PRECIP IN
THE AFTN THOUGH AS STRONG Q-VECTOR DIVERGENCE H85-H7/H7-H5 SPREADS
OVER UPPER LAKES. RESULT IS DRYING AND SUBSIDENCE IN THE H8-H7 LAYER
IN THE AFTN. THOUGH STRATOCU CLOUDS LIKELY WILL BE EXPANSIVE WITH
MOISTURE TRAPPED BENEATH SUBSIDENCE INVERSION...EXPECT POTENTIAL FOR
SHOWERS TO DIMINISH STEADILY THROUGH THE AFTN. MODEL QPF PICKING UP
ON THIS WITH MOST THAT SHOW QPF ON TUESDAY FOCUSING IT 12Z-18Z
INSTEAD OF DURING PEAK HEATING. TUESDAY WILL BE THE COOLEST DAY THIS
WEEK AS READINGS STAY IN THE 50S ALONG LK SUPERIOR OVER EAST CWA.
REST OF CWA WILL BE IN THE 60S AND LOW-MID 60S AT THAT. FAR SCNTRL
TOWARD KMNM MAY SNEAK INTO THE LOWER 70S WITH PARTIAL SUNSHINE IN
THE AFTN. DESPITE THE CHILLY AIRMASS...PRESSURE GRADIENT AND WINDS
IN LOW-LEVELS NOT VERY STRONG...SO WINDS/WAVES AND ASSOCIATED SWIM
RISK WILL REMAIN LOW.

RIDGING MOVES IN FOR WEDNESDAY-THURSDAY WHICH SHOULD KEEP WEATHER
DRY...THOUGH AN ISOLD SHRA OR SPRINKLES CANNOT BE RULED OUT DURING
PEAK HEATING ON WEDNESDAY WITH MODIFIED...BUT STILL COOL AIR ALOFT
AND SOME WEAK LARGER SCALE FORCING EXPECTED AS SHEARED OUT SHORTWAVE
IS FORECAST TO BE DROPPING ACROSS THE REGION. NAM/GFS BUFKIT
SOUNDINGS SHOW RELATIVELY NARROW DEPTH TO MOISTURE 850-800MB LEFT
OVER THE AREA...SO WILL KEEP WITH DRY FORECAST. PROBABLY ONLY WOULD
BE SPRINKLES IF ANYTHING DID OCCUR. SLIGHTLY WARMER H85 TEMPS AND
BETTER CHANCE AT SEEING SOME SUNSHINE SHOULD ALLOW HIGH TEMPS TO
REACH UPR 60S TO LOW 70S FOR MOST. STILL BLO NORMAL...BUT NOT AS
MUCH AS TUESDAY.

COULD STILL BE SOME SHRA/TSRA OVER THE UPPER MISSISSIPPI RIVER
VALLEY INTO WESTERN GREAT LAKES AS EARLY AS WEDNESDAY NIGHT OR
THURSDAY. THIS OCCURS AS SHORTWAVE CURRENTLY OVER EASTERN PACIFIC
OFF OF CA LIFTS ACROSS NORTHERN PLAINS AND MOVES EAST. SINCE THE
GREATEST INSTABILITY THROUGH H7 STAYS MOSTLY OVER NORTHERN PLAINS
INTO THURSDAY NIGHT AND THE SYSTEM IS TRUDGING INTO LOW-LEVEL SFC
RIDGE...THINK RAIN WILL HAVE TOUGH TIME MAKING IT INTO CWA THURSDAY
OR THURSDAY NIGHT. SLIGHT CHANCE POPS...BUT ONLY OVER WESTERN CWA
AND NEAR WI BORDER. CONTINUED WARMING ALOFT ON THU...BUT POTENTIAL
OF SOME MID-HIGH CLOUDS OFF SHRA/TSRA TO THE WEST MAY TEMPER MAX
TEMPS TO AROUND 70 OR INTO LOW 70S. COOLER TEMPS IN THE 60S NEAR LK
SUPERIOR WITH NORTHEAST WINDS FLOWING OUT OF THE HIGH FM HUDSON BAY
TO THE LOWER GREAT LAKES.

START TO BRING MORE WIDESPREAD SLIGHT CHANCE POPS OVER CWA ON FRIDAY
INTO FRIDAY NIGHT. SINCE GREATER INSTABILITY STAYS OVER NORTHERN
PLAINS AND FLOW IS STILL WNW ON PERIPHERY OF EASTERN CANADA
TROUGH...MOST CWA COULD END STAYING DRY AS LATEST ECMWF INDICATES.
GFS DOES SHOW SOME POTENTIAL INTO MAINLY SOUTHERN CWA. WILL KEY ON
HOW MUCH SHORTWAVE ENERGY IS PRESENT THIS FAR EAST OF INSTABILITY
GRADIENT. NEARLY IMPOSSIBLE TO PIN THAT DOWN ATTM. WARMEST TEMPS ON
FRIDAY IN THE MID-UPR 70S OVER INTERIOR EAST WITH STEADY NORTHEAST
WINDS AND LESS CHANCE OF MID-HIGH CLOUDS. PROBABLY A BETTER CHANCE
OF SHRA AND SOME TSRA FRIDAY NIGHT INTO SATURDAY WITH STRONGER
SHORTWAVE DIGGING FM THE NORTHERN PLAINS TO THE UPPER MISSISSIPPI
RIVER VALLEY. SFC LOW AND WARM FRONT SET UP OVER NORTHERN PLAINS
HELP TO BRING INCREASED H85 THETA-E RIDGING INTO UPPER LAKES WITH AN
INCREASE IN ELEVATED MUCAPE. CHANCES OF SHRA/TSRA GRADUALLY DIMINISH
BY LATE NEXT WEEKEND PER CONSENSUS OF POPS WHICH SEEMS FINE ATTM.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 120 AM EDT MON AUG 3 2015

LARGE MASS OF LOWER CLOUDS ASSOCIATED WITH EXPANSIVE LOW PRES N OF
THE GREAT LAKES WILL CONTINUE ROTATING SE AND WILL AFFECT
KIWD/KCMX/KSAW THRU THIS FCST PERIOD. ALTHOUGH VFR CONDITIONS ARE
EXPECTED TO CONTINUE WITH A WELL MIXED/DRY NEAR SFC LAYER...CIGS MAY
DROP INTO THE HIGH END OF MVFR AT KCMX AND POSSIBLY AT KSAW TODAY.
NOT OUT OF THE QUESTION THAT THERE COULD BE ISOLD -SHRA AND/OR
SPRINKLES AT TIMES AS WELL.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 325 AM EDT MON AUG 3 2015

EXPECT WNW WINDS UP TO 20 KTS INTO MID WEEK AROUND DEEP LOW PRESSURE
NEAR HUDSON BAY. THE ARRIVAL OF A HIGH PRESSURE RIDGE LATER IN THE
WEEK WILL RESULT IN LIGHT WINDS UNDER 15 KTS. NO GALES SEEN ANYTIME
SOON.
&&

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

$$

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



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