Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 191733
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
133 PM EDT SUN OCT 19 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM EDT SUN OCT 19 2014

...SCATTERED SHOWERS THIS AFTERNOON INTO EARLY EVENING BUT RAIN
AMOUNTS WILL BE LIGHT...

WV LOOP AND 00Z RAOBS SHOW QUICK WNW FLOW ALOFT WITH MAIN SHORTWAVE
CROSSING NORTHERN MANITOBA AND A SECONDARY WAVE CROSSING NORTHERN
SASKATCHEWAN. WIDESPREAD WARM AIR ADVECTION AT H85-H7 IS DRIVING
SCATTERED SHOWERS OVER MUCH OF CENTRAL MANITOBA INTO NORTHWEST
ONTARIO. DRY AIR SEEN ON 00Z SOUNDING FM KINL IS LIMITING SOUTHWARD
EXTENT OF THE RAIN THOUGH...ESPECIALLY SINCE STRONGER LARGE SCALE
FORCING REMAINS WELL TO THE NORTH. AT THE SFC...HIGH PRESSURE RIDGE
IS CURRENTLY CENTERED FM NORTHERN MO TO THE LK SUPERIOR REGION. SFC
RIDGE AND LIGHT WINDS ARE ALLOWING FOR PROBABLY THE COLDEST NIGHT
THUS FAR IN THE FALL FOR THE ENTIRE CWA WITH A LOT OF 20S AND EVEN
LOWER 30S ALONG IMMEDIATE LAKE SUPERIOR SHORE.

SFC LOW AND ASSOCIATED WARM FRONT TIED TO THE SHORTWAVES OVER
CENTRAL CANADA ARE UPSTREAM OVER MANITOBA AND THE DAKOTAS. EXPECT
HIGH CLOUDS TO THICKEN THIS MORNING AND GIVE WAY TO SCATTERED
SHOWERS LATE THIS MORNING INTO THE AFTN. PROCESS MAY TAKE A WHILE
THOUGH AS THERE IS A LOT OF DRY AIR TO OVERCOME AND THE STRONGER
FORCING TO GENERATE LIFT/SATURATION STAYS MAINLY NORTH. HOWEVER
THERE IS GOOD SIGNAL THAT WARM AIR ADVECTION MAXIMIZING H85-H75
AND MOISTURE ADVECTION WITHIN THAT LAYER AND ABOVE WILL BE
SUFFICIENT ENOUGH TO OVERCOME THE INITIAL DRY ATMOSPHERE AND
GENERATE SOME SHOWERS...ESPECIALLY OVER THE KEWEENAW AND THEN OVER
THE NCNTRL AND EASTERN CWA LATER THIS AFTN INTO THE EARLY EVENING.
USED A BLEND OF NAM/GEM-REGIONAL TO CREATE POPS/WX/QPF. NCEP WRF-ARW
AND NMM APPEARED OVERDONE WITH QPF...ESPECIALLY 15Z-21Z...GIVEN THE
INITIAL EXTENT OF DRY AIR. BASED ON SHARP DRYING ALREADY APPEARING
UPSTREAM OVER SOUTHWEST MANITOBA AND INTO SOUTHERN SASKATCHEWAN...THINK
THERE WILL BE CLEARING AFT 21Z IN THE WEST CWA. MAY SEE HIGHS TRY TO
SNEAK INTO MID 50S THERE BUT OTHERWISE...A CHILLY START WITH INCREASING
MID-HIGH CLOUDS WILL KEEP HIGHS FOR OTHER AREAS IN THE 40S TO AROUND
50 DEGREES THIS AFTN.

INTO TONIGHT...AS INITIAL SHORTWAVE SLIDES ACROSS NORTHWEST ONTARIO
THE SECONDARY WAVE IS FORECAST TO DIG MORE SOUTHEAST OVER MINNESOTA
AND WISCONSIN. RESULT IS SFC LOW TO MOVE TOWARD SOUTHEAST LK SUPERIOR
AND EASTERN UPR MICHIGAN BTWN 06Z AND 12Z. ADDITIONAL LARGER SCALE
FORCING SHOULD HELP SUSTAIN A MORE WIDESPREAD AREA OF SHOWERS THIS
EVENING FOR EAST CWA AS WELL. FARTHER WEST ACROSS CWA...ONCE WINDS
SHIFT TO THE NORTHWEST IN LOW-LEVELS AS SFC LOW CROSSES LK SUPERIOR
THERE WILL BE INCREASING LOW CLOUDS AND POSSIBLE LGT RAIN SHOWERS
FOR THE UPSLOPE AREAS OF THE WESTERN CWA. POPS WILL STAY IN THE LOW
CHANCE CATEGORY THOUGH AS DEEPER MOISTURE AND LIFT DOES NOT ARRIVE
UNTIL MONDAY. UNTIL LATE TONIGHT...MOISTURE ONLY EXTENDS TO AROUND
900-850MB AND IT REALLY IS NOT COLD ENOUGH FOR ANY LAKE PROCESSES IN
THAT LAYER YET SINCE TEMPS AT TOP OF INVERSION ARE ONLY TO AROUND 0C
BY 12Z LEADING TO DELTA T/S BARELY SUFFICIENT FOR LAKE ENHANCED
SHOWERS. MIN TEMPS ACROSS CWA WILL BE MUCH WARMER THAN TONIGHT AS
READINGS MAINLY WILL BE IN THE UPPER 30S TO AROUND 40 DEGREES.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 259 AM EDT SUN OCT 19 2014

WEAK UPPER RIDGING OVER THE AREA THIS MORNING WILL GIVE WAY TO A
SHORTWAVE DIVING SOUTHEAST OUT OF THE CANADIAN ROCKIES AND THROUGH
THE UPPER GREAT LAKES TONIGHT. AN ASSOCIATED SURFACE LOW WILL BE
LOCATED OVER EASTERN UPPER MICHIGAN AT 12Z MONDAY AND QUICKLY MOVE
SOUTHEAST AWAY FROM THE AREA ON MONDAY MORNING. WHILE MUCH OF THE
SYNOPTIC PRECIPITATION WILL BE OUT OF THE AREA ON MONDAY...ABUNDANT
LOW LEVEL MOISTURE AND COLD AIR ADVECTION WILL LEAD TO CLOUDY
CONDITIONS AND THE POTENTIAL FOR RAIN SHOWERS (ESPECIALLY OVER THE
HIGHER TERRAIN OF THE NORTHERN U.P.). THIS WILL CONTINUE INTO MONDAY
NIGHT UNTIL DRIER LOW LEVEL AIR MOVES INTO THE AREA WITH A HIGH
PRESSURE RIDGE. WILL FOCUS THE BEST POPS (HIGH END SLIGHTS AND LOW
END CHANCES) ON MONDAY IN THE UPSLOPE AREAS FAVORED BY
NORTH-NORTHWEST WINDS. SINCE DELTA-T VALUES WILL ONLY BE 8...ANY
LAKE ENHANCEMENT WILL BE LIMITED AND WILL KEEP PRECIPITATION AMOUNTS
TO A FEW HUNDREDTHS. THE PRECIP WILL FALL AS RAIN ON MONDAY WITH
CLOUD TEMPS ONLY REACHING -2C AND WETBULB0 VALUES BEING WELL ABOVE
1.5KFT. AS WINDS VEER TO THE NORTHEAST ON MONDAY NIGHT DUE TO THE
APPROACHING HIGH PRESSURE RIDGE FROM ONTARIO...EXPECT A TRANSITION
TO UPSLOPE LOCATIONS FAVORED BY THAT WIND DIRECTION (PRIMARILY OVER
THE NORTH CENTRAL U.P.). ALTHOUGH WETBULB0 HEIGHTS WOULD SUPPORT
SOME SNOW MIXING IN ON MONDAY NIGHT OVER THE HIGHER TERRAIN OF
THE NORTH CENTRAL U.P....THERE WILL BE A LIMITED POTENTIAL FOR ICE
CRYSTALS IN THE CLOUD AND WILL STICK WITH RAIN. SINCE INVERSION
HEIGHTS WILL BE LOWERING DURING MONDAY NIGHT...WILL SLOWLY LOWER THE
POPS AND HAVE THEM DIMINISHED BY SUNRISE ON TUESDAY. STILL EXPECT
THE CLOUDS TO LINGER OVER PORTIONS OF NORTHERN UPPER MICHIGAN INTO
TUESDAY MORNING BEFORE THE DRYING FROM THE HIGH REALLY TAKES HOLD.
THIS HIGH WILL THEN LEAD TO MOSTLY CLEAR SKIES TUESDAY AFTERNOON
INTO WEDNESDAY WHILE THE UPPER RIDGE BUILDS OVER THE REGION. AS FOR
TEMPS DURING THIS PERIOD...EXPECT THE COOLEST HIGHS ON
MONDAY/TUESDAY (MID 40S TO LOWER 50S) AND THEN WARMING WEDNESDAY TO
NORMAL OR SLIGHTLY ABOVE NORMAL VALUES.

FOR THE REST OF THE WORK WEEK...THE AREA WILL BE ON THE NORTHEAST
EDGE OF AN UPPER RIDGE OVER THE WESTERN/CENTRAL CONUS...LEADING TO
NORMAL OR SLIGHTLY ABOVE NORMAL TEMPERATURES. THE MAIN
PRECIPITATION CHANCE WILL COME LATE WEDNESDAY NIGHT INTO THURSDAY
AS A SHORTWAVE AND ASSOCIATED COLD FRONT SHIFTS EAST ACROSS THE
AREA. SINCE THE PARENT LOW WILL BE LOCATED WELL TO THE NORTH IN
CANADA...EXPECT THE PRECIP AMOUNTS TO BE LIGHT AND WILL KEEP THE
POPS IN THE SLIGHT CHANCE CATEGORY. BEHIND THIS FRONT...A HIGH
PRESSURE RIDGE WILL BUILD BACK OVER THE REGION THROUGH FRIDAY AND
LEAD TO DRY WEATHER AND ABOVE NORMAL TEMPERATURES. A WEAK LOW DOES
APPEAR TO NEAR THE REGION ON SATURDAY...BUT MOISTURE APPEARS TO BE
LIMITED.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 132 PM EDT SUN OCT 19 2014

VFR CONDITIONS INITIALLY WILL SLOWLY FALL TO MVFR AND EVEN POSSIBLY
IFR OVERNIGHT BEHIND LOW PRESSURE THAT WILL BE CROSSING OVERHEAD.
THIS WILL BRING ABOUT FAVORABLE NW FLOW...AND AS WHAT HAS ALREADY
BEEN SEEN UPSTREAM ACROSS MANITOBA AND ONTARIO...PLENTY OF LOW
CLOUDS. THE BEST CHANCE OF IFR CEILINGS WILL BE AT SAW AROUND
DAYBREAK WEDNESDAY...KEPT THEM AT MVFR FOR NOW GIVEN THE
UNCERTAINTY. COOL LAKE ENHANCED RAIN SHOWERS WILL BE POSSIBLE LATE
TONIGHT THROUGH MUCH OF THE DAY MONDAY.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 AM EDT SUN OCT 19 2014

NO GALES ARE EXPECTED FOR THE UPCOMING WEEK WITH WINDS STAYING BLO
30 KTS. PRIMARY PERIOD OF STRONG WINDS WILL BE THIS AFTERNOON INTO
THIS EVENING WITH SOUTH WINDS TO 25 KTS OVER EASTERN LK SUPERIOR
AHEAD OF A SFC LOW DROPPING FROM MANITOBA SOUTHEAST TOWARD LK
SUPERIOR. ONCE THE SFC LOW SLIDES ACROSS THE LAKE TONIGHT...WINDS
WILL SWITCH TO THE NORTHWEST LATE TONIGHT INTO MONDAY AND MAY
AGAIN REACH 25 KTS MONDAY AFTERNOON AND MONDAY EVENING...ESPECIALLY
OVER CNTRL AND EASTERN LK SUPERIOR. BEYOND MONDAY EVENING...WINDS
WILL MAINLY BE BELOW 20 KTS AS PRESSURE GRADIENT IS WEAK.
&&

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

$$

SHORT TERM...JLA
LONG TERM...SRF
AVIATION...KF
MARINE...JLA






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