000
FXUS63 KMQT 201736
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
136 PM EDT MON MAY 20 2013

.UPDATE...
ISSUED AT 1000 AM EDT MON MAY 20 2013

BASED ON DRYNESS ARND H85 AS SHOWN ON THE 12Z GRB RAOB...WHERE THE
H85 DEWPT DEPRESSION WAS 11C...TENDED TO TRIM POPS A BIT FOR TODAY.
LATEST RUC MODEL SHOWS THIS DRY AIR OVERSPREADING THE CWA THRU THE
AFTN. MAINTAINED THE HIER CHC POPS OVER THE E HALF OF THE CWA...
WHERE HIER H85 DEWPTS ARE PROGGED TO LINGER LONGER.
&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 449 AM EDT MON MAY 20 2013

UPPER AIR PATTERN CONSISTS OF A CLOSED 500 MB LOW OVER SD WITH A
DEEP TROUGH ACROSS THE PLAINS STATES AND A 500 MB RIDGE IN THE UPPER
GREAT LAKES. THE RIDGE GETS PUSHED FURTHER TO THE EAST OVER THE
LOWER GREAT LAKES THIS FORECAST PERIOD WHILE THE TROUGH HEADS SLOWLY
EAST WITH THE 500 MB LOW NOT MOVING VERY MUCH AT ALL.

850-500 MB Q-VECTOR CONVERGENCE AND DEEP MOISTURE REMAIN FOR THIS
FORECAST PERIOD AND THE NAM...ECMWF AND GFS SHOW THIS. TRICKY
FORECAST COMING UP WITH AMOUNT OF CLOUD COVER DUE TO CONVECTION
BEING HARD TO DETERMINE AND THIS OF COURSE WILL HAVE AN EFFECT ON
TEMPERATURES. THE MORE SUN THAT WE SEE...THE WARMER THE TEMPERATURES
WILL BE AND THE GREATER THE INSTABILITY FOR THE THUNDERSTORMS TO
WORK WITH. TEMPERATURES HAVE A BIG BUST POTENTIAL FOR TODAY WITH
CLOUD COVER BEING THE BIG QUESTION. THOUGHT THERE WOULD BE SOME
LIMITED SUNSHINE AND ENDED UP WARMING HIGH TEMPERATURES A FEW
DEGREES...ESPECIALLY OVER THE EAST WHERE THAT AREA IS FURTHER FROM
THE STRONG FORCING AND HAS SOME DRIER AIR AWAY FROM THE SFC WARM
FRONT. DID GRADUALLY BRING HIGH POPS OVER THE CWA TODAY AS SYSTEM
DRAWS CLOSER AND KEPT LIKELY POPS IN FOR TONIGHT AS THERE WILL
PROBABLY BE AN MCS/MCC IN THE AREA BRINGING WIDESPREAD RAINFALL TO
THE AREA. DID NOT HAVE ANY TIME TO LOOK AT SEVERE WEATHER
POTENTIAL...BUT THINKING IS THERE COULD BE A FEW STORMS WITH STRONG
WINDS AND LARGE HAIL AND THE SLIGHT RISK ACROSS THE SOUTHERN CWA
LOOKED REASONABLE. ALL DEPENDS ON AMOUNT OF SUNSHINE SEEN TO THE
SOUTH OF THE AREA AND THAT IS THE QUESTION THAT CANNOT BE ANSWERED
AT THIS TIME.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 515 AM EDT MON MAY 20 2013

THE NEARLY STEADY STATE 500MB LOW TO OUR WEST WILL CONTINUE TO SPIN
ACROSS THE EASTERN DAKOTAS AND WESTERN MN AT 12Z TUESDAY. EXPECT THE
LOW TO SLIDE EASTWARD ON WEDNESDAY...MERGING WITH THE STRONGER LOW
SPINNING OVER EASTERN HUDSON BAY/NORTHERN QUEBEC. THE BEST CHANCE
FOR CONVECTION WILL LINGER ACROSS THE WI BORDER TUESDAY INTO TUESDAY
EVENING...BEFORE SLOWLY COMING TO AN END. FOG OVER LAKE SUPERIOR
WILL SLOWLY BEGIN TO PUSH TO FAR SOUTHERN PORTIONS OF THE
LAKE...WITH LAKE MICHIGAN FOG LIKELY REMAINING STRONG THROUGH MUCH
OF WEDNESDAY WHEN THE DEEPER MOISTURE EXITS THE REGION.

EXPECT COOL NORTHERLY FLOW TO BE THE RULE FROM THURSDAY ON...AS THE
REINFORCING 500MB TROUGH PUSHES IN FROM THE NW. THE LAST OF THE RAIN
SHOULD BE EXITING EASTERN UPPER MI THURSDAY MORNING. DRY WEATHER
SHOULD BE THE RULE FROM THURSDAY AFTERNOON THROUGH AT LEAST THE END
OF THE FORECAST PERIOD /SUNDAY/...AS HIGH PRESSURE DOMINATES THE
REGION.

850MB TEMPS OFF THE 19/12Z ECMWF FALL TO A RATHER COOL 0 TO -3C
THURSDAY NIGHT INTO EARLY FRIDAY...AS COOL HIGH PRESSURE SINKS IN
FROM THE NNW. THE 20/00Z RUN WARMED UP SLIGHTLY AND LINED UP A BIT
BETTER WITH THE GFS...AROUND 0 TO 2C FRIDAY THROUGH SATURDAY. THE
NORMAL HIGH TEMPS FOR THIS TIME OF YEAR ARE IN THE MID 60S FOR MUCH
OF THE CWA...TO NEAR 70F SOUTH CENTRAL AND NEAR THE WI BORDER. WE
SHOULD BE WELL BELOW NORMAL FOR HIGH TEMPS...IN THE 50S ON THURSDAY.
FRIDAY WILL NOT BE MUCH WARMER...WITH A FEW READINGS IN THE LOW TO
MID 60S NEAR THE WI BORDER.

A HIGH AMPLITUDE RIDGE ACROSS THE CENTRAL U.S. UP THROUGH CENTRAL
CANADA WILL CONTINUE TO BUILD...THANKS THE THE BOOKEND 500MB LOWS
OVER THE PACIFIC NORTHWEST AND ACROSS QUEBEC. LOOK FOR THIS RIDGE TO
SLOWLY EDGE EASTWARD...AND RIGHT ACROSS WI/MN/WESTERN UPPER MI AND
LAKE SUPERIOR BY DAYBREAK MONDAY. WARMER AIR WILL SLOWLY CREEP BACK
IN...BUT WITH NO GREAT SOUTHERLY RETURN FLOW...TEMPERATURES WILL
ONLY MODERATE SLIGHTLY EACH DAY...WITH BELOW NORMAL READINGS AND
RELATIVELY LIGHT WINDS STILL BY SUNDAY AS THE LARGE/STRONG HIGH
PRESSURE SYSTEM CENTERED OVER MUCH OF ONTARIO SINKS CLOSER TO THE
AREA. WHILE BOTH THE GFS AND ECMWF HINT AT A COUPLE OF SHORTWAVES
SINKING IN ON THE NW FLOW ALOFT OVER THE UPCOMING WEEKEND. AT THIS
POINT THERE DOESN/T LOOK TO BE ENOUGH MOISTURE AROUND TO RESULT IN
ANYTHING MORE THAN A FEW CLOUDS. IF ANY SHOWERS OR TS DEVELOP...THEY
WILL LIKELY REMAIN NORTH AND EAST...CLOSER TO THE 500MB AND SFC LOW
ACROSS QUEBEC.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 134 PM EDT MON MAY 20 2013

CHALLENING AVIATION FCST TODAY. BUT WITH CWA N OF SFC WARM FNT AND
STEADY UPSLOPE E-SE WIND...EXPECT PREDOMINANT IFR CONDITIONS TO
PERSIST THRU THE FCST PERIOD AT SAW AND ESPECIALLY CMX...WHERE
LIFR/VLIFR CONDITIONS WL PREVAIL INTO THIS EVNG. DOWNSLOPING FLOW
AND DAYTIME HEATING/MIXING SHOULD MAINTAIN VFR CONDITIONS AT IWD
THRU THE AFTN...BUT EXPECTED WSHFT TO THE NE OFF COOL/MOIST LK SUP
THIS EVNG/TUE SHOULD BRING IFR CONDITIONS OVER THAT SITE.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 449 AM EDT MON MAY 20 2013

THE MAIN THREATS FOR THIS PERIOD WILL BE A FEW HIGHER GUSTS AT THE
HIGHEST OBSERVING PLATFORMS...AND THE POTENTIAL FOR FOG. A FEW GUSTS
OF 30-35KTS POSSIBLE THROUGH MONDAY...WITH MOST SITES ABOUT 10KTS
LOWER THANKS TO THE MARINE LAYER. HAVE ALREADY HAD REPORTS OF AROUND
2-5SM VIS OVER W LAKE SUPERIOR...WHICH WILL LIKELY CONTINUE AND
SLOWLY SPREAD E WITH THE BETTER CHANCE OF SHOWERS TODAY. EXPECT FOG
TO LINGER THROUGH TUESDAY /FOR MAINLY S LAKE SUPERIOR/.

EXPECT A RIDGE OVER N MANITOBA TO SLIDE ACROSS JAMES BAY
TONIGHT...AND EXIT E ACROSS QUEBEC TUESDAY NIGHT. IN THE
MEANTIME...A LOW OVER THE EASTERN DAKOTAS AND WESTERN MINNESOTA
TODAY AND TONIGHT SHOULD FILL SLIGHTLY ACROSS SOUTHERN MINNESOTA AND
CENTRAL WISCONSIN ON TUESDAY...AND SLOWLY OVER STRETCHING FROM
SOUTHERN WISCONSIN TO LOWER MICHIGAN DURING THE DAY WEDNESDAY. THE
LOW WILL FINALLY EXIT E ACROSS THE LOWER GREAT LAKES WEDNESDAY
NIGHT. BEHIND THE LOW...STRONG AND COOL HIGH PRESSURE ACROSS N
CENTRAL CANADA WILL EXTEND A RIDGE ACROSS LAKE SUPERIOR LATE
THURSDAY AFTERNOON THROUGH AT LEAST FRIDAY...AND MOST LIKELY THROUGH
THE WEEKEND.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
  GALE WARNING UNTIL 11 PM EDT /10 PM CDT/ THIS EVENING FOR LSZ162.

LAKE MICHIGAN...
NONE.
&&

$$

UPDATE...KC
SHORT TERM...07
LONG TERM...KF
AVIATION...KC
MARINE...KF