Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 310852
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
452 AM EDT FRI JUL 31 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 452 AM EDT FRI JUL 31 2015

LIKE YESTERDAY...A COUPLE SHORTWAVE DROPPING SOUTHEAST ACROSS THE
AREA WILL BE THE MAIN FEATURES CONTROLLING THE WEATHER FOR THE AREA
TODAY. THE FIRST SHORTWAVE IS CURRENTLY DROPPING SOUTHEAST ACROSS
LAKE SUPERIOR AND WESTERN UPPER MICHIGAN. AT THE SURFACE...THERE IS
A WEAK TROUGH OF 1009MB AT OVER CENTRAL LAKE SUPERIOR. THERE WERE
SHOWERS EARLIER IN THE NIGHT...BUT MOST HAVE SINCE DIMINISHED AND
THERE ARE ONLY A FEW SHOWERS NORTHEAST AND SOUTHWEST OF THE KEWEENAW
AT 430AM. THESE WEAK SHOWERS SHOULD CONTINUE EAST WITH LIMITED
PRECIPITATION POTENTIAL. AS THE SHORTWAVE AND TROUGH CONTINUE EAST
THIS MORNING..COULD SEE SOME REDEVELOPMENT OVER THE FAR EASTERN CWA
AS DIURNAL HEATING DEVELOPS. BUT LATEST TRENDS IN THE MODELS ARE
STARTING TO BACK AWAY FROM THAT IDEA...LARGELY DUE TO THE FASTER
ARRIVAL OF THE SHORTWAVE AND SURFACE TROUGH...WHICH WILL LIKELY PUSH
IT THROUGH TOO EARLY FOR MUCH OF THE EASTERN CWA. WILL CONTINUE TO
MONITOR OVER THE NEXT COUPLE OF HOURS...BUT MAY NEED TO TREND DOWN
THE CHANCE POPS IN PLACE IN THAT AREA. SHIFTING THE FOCUS TOWARDS
THE CENTRAL CWA...DO THINK THAT ISOLATED TO MAYBE EVEN SCATTERED
SHOWERS AND THUNDERSTORMS WILL DEVELOP IN THE NORTH CENTRAL U.P. AND
LARGELY WITH DIURNAL HEATING AND ALONG A WEAK CONVERGENCE ZONE DUE
TO VEERING WINDS FROM A SUBTLE LAKE BREEZE (EASTERN MARQUETTE INTO
WESTERN ALGER AND NORTHERN DELTA COUNTIES). BEST INSTABILITY IS TO
THE EAST OF THE AREA IN CHIPPEWA/MACKINAC COUNTIES (ML CAPE OF
NEARING 1000 J/KG)...BUT STILL SHOULD SEE VALUES AROUND 500-750 OVER
THE EASTERN CWA. LIKE YESTERDAY...AN INVERTED-V LOOK TO THE SOUNDING
(DCAPES AHEAD OF MODEL CONVECTION SHOWS VALUES APPROACHING 800-1000
J/KG) WILL LEAD TO THE POTENTIAL FOR BRIEF GUSTY WINDS WITH ANY OF
THE STRONGER THUNDERSTORMS.

THE SECOND SHORTWAVE IS CURRENTLY NEAR LAKE WINNIPEG AND WILL FOLLOW
A SIMILAR AND MAYBE SLIGHTLY FARTHER TO THE SOUTHWEST TRACK AS THE
ONE THIS MORNING. THIS WAVE WILL BE REACHING THE WESTERN U.P. AROUND
MID-LATE AFTERNOON AND WILL TAKE ADVANTAGE OF PEAK HEATING TO LEAD
TO THE POSSIBILITY OF SHOWERS OVER THE INTERIOR WEST LATE THIS
AFTERNOON. OVERALL...THINK MOST OF THE SHOWERS WILL ARRIVE FROM THE
NORTHWEST...SHIFTING SOUTHEAST INTO THE AREA FROM THE TIP OF THE MN
ARROWHEAD AND AND NORTHWEST ONTARIO. HIGH RESOLUTIONS MODELS MATCHED
THAT IDEA...ALONG WITH NCAR ENSEMBLE WRF NEIGHBORHOOD
PROBABILITIES...SO HAVE SPREAD SLIGHT/CHANCE POPS SOUTHEAST FROM
THAT AREA LATE IN THE AFTERNOON AND INTO THE EVENING BEFORE SLOWLY
DIMINISHING OVERNIGHT.

OUTSIDE OF THE SHORTWAVES...WILL CONTINUE TO SEE SOME GUSTY WINDS
OUT THERE TODAY...BUT EXPECT THEM TO BE A LITTLE LOWER THAN THE LAST
2 DAYS DUE TO SLIGHTLY LOWER WITH THE MIXED LAYER WINDS. THAT BEING
SAID...WITH MEAN MOMENTUM TRANSFER VALUES INDICATING GUSTS IN THE
LOW 20KT RANGE THIS AFTERNOON...HAVE FOLLOWED SUIT WITH THE GUST
FORECAST. HAVE THE HIGHEST GUSTS OVER THE KEWEENAW DUE TO THE MORE
EXPOSED LOCATIONS AND BEING WITHIN A POCKET OF STRONGER 925MB WINDS.
THINK THERE WILL BE MORE WIDESPREAD DIURNAL CU TODAY AND HAVE PUSHED
SOME AREAS OVER THE CENTRAL INTO THE MOSTLY CLOUDY CATEGORY.
THIS...COMBINED WITH LOW LEVEL TEMPS BEING A TOUCH COOLER THAN
YESTERDAY...WILL PRODUCE HIGHS A TOUCH COOLER THAN YESTERDAY. WILL
NEED TO KEEP AN EYE ON FIRE WEATHER CONDITIONS AGAIN TODAY...AS THE
DRY LOW LEVEL AIR SHOULD LEAD TO RH VALUES MIXING OUT INTO THE 30S
FOR AREAS OUTSIDE OF THE RAIN SHOWERS. WITH THE CONTINUED WINDY AND
DRY CONDITIONS...WILDFIRE POTENTIAL WILL REMAIN HEIGHTENED.

FINALLY FOR TONIGHT...THERE ARE HINTS AT ANOTHER SHORTWAVE DROPPING
SOUTHEAST ACROSS THE AREA OVERNIGHT TONIGHT. MODELS ARE VARYING ON
THE INTENSITY AND LOCATION OF THE WAVE AND WITH LITTLE NOTICEABLE
FEATURE UPSTREAM...WON/T GO TOO HIGH ON POPS BUT WILL FOLLOW A
SIMILAR SITUATION AS THIS PAST NIGHT WITH SLIGHT CHANCE POPS OVER
NORTHERN LAKE SUPERIOR AND DIMINISHING THROUGH THE NIGHT AS THEY
SLIDE SOUTHEAST.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 345 AM EDT FRI JUL 31 2015

NAM SHOWS A STRONG 500 MB RIDGE OVER THE WESTERN U.S. 12Z SAT WITH A
TROUGH OVER THE LOWER GREAT LAKES. NAM CONTINUES TO HAVE NORTHWEST
UPPER FLOW OVER THE UPPER GREAT LAKES THIS FORECAST PERIOD WITH
UPPER LEVEL TROUGHING NEARBY. WHAT THIS WILL MEAN IS A COOLING
TREND. THERE WILL BE SOME CHANCE POPS IN FOR SUN AFTERNOON AND
SUNDAY EVENING AS A SHORTWAVE MOVES THROUGH THE AREA. DID NOT MAKE
TOO MANY CHANGES TO THE GOING FORECAST OVERALL.

IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB RIDGE OVER THE WESTERN
U.S. 12Z MON WITH A DEEP TROUGH OVER ONTARIO INTO THE EASTERN U.S.
THIS DEEP TROUGH REMAINS STATIONARY 12Z TUE WITH LITTLE CHANGE INTO
WED AND THU. A COLD FRONT MOVES THROUGH ON MON AND THEN SLOWLY MOVES
SOUTH AND STALLS OUT WELL SOUTH OF THE AREA THIS FORECAST PERIOD.
TEMPERATURES LOOK TO BE BELOW NORMAL FOR THIS FORECAST PERIOD AS
WELL.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 140 AM EDT FRI JUL 31 2015

VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW THRU THIS FCST PERIOD
AS LOW-LEVEL AIR MASS REMAINS DRY. WINDS WILL BECOME GUSTY WNW TO 20-
25KT WITHIN A FEW HRS AFTER SUNRISE WITH STRONGEST WINDS AGAIN AT
THE MORE EXPOSED KCMX TERMINAL. A PAIR OF DISTURBANCE MOVING ESE
INTO THE UPPER GREAT LAKES WILL GENERATE ISOLD TO SCT SHRA/TSRA
DURING THIS FCST PERIOD...ESPECIALLY DURING THE DAYLIGHT HRS.
CONFIDENCE IN PCPN IS HIGH ENOUGH TO INCLUDE A VCSH MENTION AT ALL
TERMINALS FOR AT LEAST SOME PORTION OF THE FCST PERIOD. KSAW WILL
PROBABLY HAVE THE BEST POTENTIAL FOR VCSH DUE TO BETTER ALIGNMENT OF
INSTABILITY AND THE TRACK OF DISTURBANCES. IF A SHRA OR A TSRA
AFFECTS ANY OF THE TERMINALS...A BRIEF PERIOD OF MVFR CONDITIONS
WILL BE POSSIBLE.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 452 AM EDT FRI JUL 31 2015

A LOW SPINNING OVER SOUTHERN HUDSON BAY WILL SWEEP A SERIES OF
TROUGH ACROSS LAKE SUPERIOR THROUGH THIS WEEKEND. A TROUGH
MOVING ACROSS EASTERN LAKE SUPERIOR THIS MORNING WILL REINFORCE
WESTERLY WINDS OF 10-20KTS WITH A FEW GUSTS UP TO 25KTS. WINDS WILL
REMAIN IN THE 10-20KT RANGE THROUGH THE START OF THE WEEKEND. A
BROAD SURFACE TROUGH WILL MOVE ACROSS THE UPPER GREAT LAKES REGION
ON SUNDAY BEFORE HIGH PRESSURE FROM THE CANADIAN PRAIRIES GRADUALLY
MOVES INTO THE REGION FOR THE START OF NEXT WEEK.
&&

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

$$

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



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