Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 301743
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
143 PM EDT THU JUL 30 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 445 AM EDT THU JUL 30 2015

THE LOW PRESSURE SYSTEM THAT BROUGHT THE GUSTY WEST-SOUTHWEST WINDS
TO THE AREA YESTERDAY IS MOVING OUT OF FAR NORTHERN ONTARIO AND INTO
HUDSON BAY. AS THIS IS OCCURRING...IT IS SWEEPING A SURFACE TROUGH
AND SHORTWAVE SOUTHEAST ACROSS THE UPPER GREAT LAKES THIS MORNING
(CURRENTLY STRETCHING SOUTHWEST ACROSS WESTERN LAKE SUPERIOR). THERE
ARE SCATTERED TO BROKEN CLOUDS ALONG AND AHEAD OF THE TROUGH...WITH
THE MOISTURE BEING MOST PROMINENT BETWEEN 800-650MB AS SEEN ON THE
00Z KINL SOUNDING. ARE SEEING LOWER CLOUDS UPSTREAM TO THE NORTH IN
NORTHWESTERN ONTARIO WHERE RAP ANALYSIS DATA IS SHOWING BETTER
MOISTURE BETWEEN 925-850MB. MOST OF THE SHOWERS ASSOCIATED WITH THIS
WAVE ARE IN NORTHWEST ONTARIO AND FAR NORTHERN LAKE SUPERIOR IN
ASSOCIATION WITH THAT DEEPER MOISTURE. STILL SEEING GUSTY WESTERLY
WINDS OVER THE KEWEENAW AND LAKE SUPERIOR...WITH THE KCMX GUSTING TO
27KTS AT 353AM. INLAND AREAS HAVE DECOUPLED AND ARE GENERALLY INT HE
5-10KT RANGE.

AS THE TROUGH OVER THE WESTERN LAKE MOVES ACROSS THE AREA THIS
MORNING...WINDS WILL SHIFT MORE OUT OF THE WEST-NORTHWEST AND BECOME
GUSTY. EXPECT THE STRONGEST GUSTS THROUGH EARLY AFTERNOON...20-25KTS
FOR MOST AREAS AND SLIGHTLY HIGHER OVER THE KEWEENAW...BEFORE
GRADUALLY DIMINISH INTO THE EVENING. NEXT WAVE (CURRENTLY MOVING
INTO SOUTHWESTERN MANITOBA AND NORTHERN NORTH DAKOTA) WILL SLIDE
ACROSS THE AREA LATE THIS MORNING AND THIS AFTERNOON. WITH THE
ASSISTANCE OF DIURNAL HEATING THE THE DEEPER MOISTURE WITH THE
WAVE...WOULD EXPECT SOME SHOWERS/THUNDERSTORMS TO DEVELOP/MOVE INTO
THE AREA THIS AFTERNOON. MODELS FAIRLY CONSISTENT ON THEM OCCURRING
OVER NORTHWEST WISCONSIN AND WESTERN UPPER MICHIGAN NEAR THE
WISCONSIN BORDER...WHERE THE DIURNAL HEATING CAN BE MAXIMIZED AWAY
FROM THE STABILIZING INFLUENCE OF LAKE SUPERIOR. ALSO EXPECT SOME
SHOWERS MOVING OUT OF THE MN ARROWHEAD IN THE AFTERNOON AND ACROSS
WESTERN LAKE SUPERIOR...WHICH COULD AFFECT THE KEWEENAW TOWARD
EVENING...BUT HAVE KEPT THE POPS JUST TO THE WEST FOR NOW.

MODELS VARY SIGNIFICANTLY IN THE AMOUNT OF INSTABILITY (BETWEEN 300-
1400 J/KG)...AND BELIEVE THE ML CAPE VALUES WILL FALL IN THE MIDDLE
GROUND AND AROUND 700-800 J/KG BASED OFF A CONSENSUS AND 03Z SREF
PROBABILITIES ONLY AROUND 10 PERCENT FOR VALUES OVER 1000 J/KG. SO
THERE WILL BE INSTABILITY TO WORK WILL. PLENTY OF SHEAR TO WORK WITH
(0-6KM BULK SHEAR VALUES OF 40-50KTS)...WHICH MAY BE A LITTLE TOO
MUCH WITH THE AMOUNT OF INSTABILITY AVAILABLE. IN ADDITION...THE
CAPE IS FAIRLY TALL/SKINNY (NCAPE VALUES AT OR BELOW 0.1 IN MOST
LOCATIONS)...SO DON/T THINK HAIL IS MUCH OF A THREAT. WOULD LIKELY
BE GUSTY WINDS IF THERE ARE STRONGER STORMS DUE TO THE INVERTED-V
LOOK OF THE SOUNDINGS THIS AFTERNOON (ALTHOUGH DCAPE LOOKS TO BE
BEST INTO NORTHWEST WISCONSIN). ANY SHOWERS/THUNDERSTORMS SHOULD
QUICKLY DIMINISH THIS EVENING AS THE SHORTWAVE DEPARTS AND DIURNAL
HEATING IS LOST.

THE NEXT IN THE SERIES OF SHORTWAVES THAT WILL CONTINUE INTO THE
WEEKEND WILL MOVE INTO THE NORTHWEST CWA TONIGHT. STILL SOME
DDIFFERENCESIN THE WAVE TIMING/TRACK IN THE MODELS...BUT THEY ARE
SHOWING LESS MOISTURE AVAILABLE OVER THE U.P....SO WILL KEEP ANY
POPS OVER LAKE SUPERIOR FOR OVERNIGHT TONIGHT.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 526 AM EDT THU JUL 30 2015

THE OVERALL PATTERN AFFECTING THE AREA WILL NOT CHANGE MUCH THROUGH
THE LONG TERM AS A PERSISTENT CLOSED LOW NEAR HUDSON BAY WILL KEEP A
BROAD TROUGH ENTRENCHED OVER MUCH OF ERN CANADA WHILE A BROAD RIDGE
REMAINS ANCHORED OVER THE WRN CONUS. BETWEEN THESE LARGE SCALE
FEATURES A NW FLOW WILL DOMINATE THE GREAT LAKES REGION ALLOWING A
SERIES OF MAINLY WEAK AND MOISTURE STARVED SHORTWAVES TO PASS THRU
AREA RESULTING IN PERIODIC LIGHT PCPN. TYPICALLY...THESE WEAK
SHORTWAVES ARE POORLY RESOLVED BY MODELS WHICH WILL MAKE FOR A
TRICKY FCST IN THE LONG TERM. IT LOOKS LIKE TEMPERATURES WILL BE
NEAR NORMAL THROUGH THE WEEKEND AND THEN PERHAPS TREND BELOW NORMAL
FOR THE EARLY PART OF NEXT WEEK BEHIND AS A MORE AMPLIFIED SHORTWAVE
AND ASSOC COLD FRONT PASS THROUGH THE UPPER GREAT LAKES REGION.

FRI INTO SAT...MOST OF MODELS HINT AT A FEW WEAK SHORTWAVES MOVING
THROUGH THE AREA...ONE FRI MORNING AND ANOTHER FRI NIGHT. WITH
SEVERAL OF THE MODELS SHOWING 100-300 J/KG OF MLCAPE AHEAD OF THESE
WAVES WILL PROBABLY NEED TO MAINTAIN AT LEAST SLIGHT CHC POPS FOR
ISOLD SHRA/TSRA. WITH LIMITED MOISTURE IN NW FLOW EXPECT ANY PCPN
FROM ISOLD CONVECTION TO BE FAIRLY LIGHT.

SATURDAY LOOKS TO BE TRENDING DRIER AS MOST OF THE MODELS INDICATE
SHORTWAVE ENERGY PASSING EAST OF THE AREA SAT MORNING...ALTHOUGH A
POCKET OF HIGHER INSTABILITY NOTED ALONG LAKE MI COUNTIES MAY STILL
WARRANT SLIGHT CHC POPS THERE.

TEMPERATURES FRI THROUGH SAT WILL BE CLOSER TO NORMAL WITH HIGHS IN
THE 70S TO LOWER 80S AND LOWS IN THE 50S TO LOWER 60S.

MODELS COMING INTO A LITTLE BETTER AGREEMENT ON TIMING OF STRONGER
SHORTWAVE COMING DOWN FM SCNTRL CANADA AND ASSOC COLD FROPA FOR SUN
NIGHT/MON TIME FRAME. WILL CONTINUE LOW CHC POPS 30-40 PCT AT THIS
TIME...AND GIVEN STRENGTH OF SHORTWAVE THIS MAY BE BEST OPPORTUNITY
TO SEE WIDEPSREAD ALBEIT LIGHT PCPN. MODELS ADVERTISE BELOW NORMAL
TEMPS FOR MON-WED IN THE WAKE OF THE FROPA AS LATEST 00Z ECMWF SHOWS
8H TEMPS DROPPING TO 4-6C BY MON EVENING AND THEN PERSISTING IN THAT
RANGE INTO WED.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 142 PM EDT THU JUL 30 2015

VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW THRU THIS FCST PERIOD
AS LOW-LEVEL AIR MASS REMAINS RELATIVELY DRY. WINDS WILL DECREASE
THIS EVENING AND TONIGHT. THERE MAY BE ISOLATED SHRA NEAR KIWD LATE
THIS AFTERNOON...BUT POTENTIAL OF DEVELOPMENT AND EXPECTED COVERAGE
IS LOW ENOUGH TO ONLY INCLUDE VCSH IN TAF.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 445 AM EDT THU JUL 30 2015

A LOW SPINNING OVER SOUTHERN HUDSON BAY WILL SWEEP A SERIES OF
TROUGH ACROSS LAKE SUPERIOR THROUGH THIS WEEKEND. THE TROUGH THAT
MOVES THROUGH EARLY THIS MORNING WILL SHIFT WINDS TO THE WEST-
NORTHWEST AND COULD PRODUCE A FEW GALE FORCE GUSTS TO 35 KNOTS
THROUGH MID-DAY TODAY. THEN...WINDS ARE EXPECTED TO SLOWLY DIMINISH
THIS AFTERNOON INTO TONIGHT AS THE PRESSURE GRADIENT WEAKENS AND
REMAIN IN THE 10 TO 20KT RANGE INTO THE START OF THE WEEKEND.
&&

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

$$

SHORT TERM...SRF
LONG TERM...VOSS
AVIATION...TITUS
MARINE...SRF



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