Area Forecast Discussion Issued At 501 AM EDT THU APR30 2015

Area Forecast Discussion

Issued by NWS Marquette, MI

000

FXUS63 KMQT 061139

AFDMQT

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE MARQUETTE MI

739 AM EDT WED MAY 6 2015

.SHORT TERM...(TODAY AND TONIGHT)

ISSUED AT 428 AM EDT WED MAY 6 2015

A GENERALLY QUIET DAY IS IN STORE WITH VERY SMALL CHANCES OF LIGHT

RAIN SHOWERS ALONG THE WI BORDER THIS MORNING.

A PRONOUNCED MID-LEVEL RIDGE AXIS EXTENDING FROM NORTH DAKOTA TO THE

OHIO VALLEY IS SLOWLY SHIFTING ENE. MEANWHILE...DEEP TROUGHING

ACROSS THE PAC NW IS KICKING OUT A SLOW-MOVING MID-LEVEL LOW ACROSS

THE CENTRAL ROCKIES. A BROAD SFC TROUGH SPANNING THE EXTENT OF THE

U.S. ROCKIES WILL CONSOLIDATE OVER THE DAKOTAS IN RESPONSE TO THIS

MID-LEVEL LOW.

AS OF 08Z...A NARROW LINE OF RAIN SHOWERS STRETCHING FROM NEAR

BRAINERD MN TO GREEN BAY TO MUSKEGON CONTINUES TO LIFT ENE EARLY

THIS MORNING. THIS BAND OF SHOWERS IS TIED TO A WARM FRONT/THETA-E

ADVECTION IN A LAYER FROM 925 TO 850 HPA. OUTSIDE OF THIS...FORCING

IS MINIMAL. WHILE THESE SHOWERS HAVE BEEN ABLE TO MAINTAIN

THEMSELVES ACROSS WI DURING THE OVERNIGHT...THE STRENGTHENING MID-

LEVEL RIDGE AND VERY DRY SFC AIR ACROSS THE CWA WILL ALLOW FOR THE

SHOWERS TO GRADUALLY DIMINISH THIS MORNING AS THEY CROSS INTO UPPER

MI. TRENDS OFF THE KGRB RADAR SHOW THAT THE BULK OF THE

REFLECTIVITIES ACROSS CENTRAL WI ARE STRUGGLING TO MATERIALIZE NEAR

THE SFC. IN FACT...AREA OBS INDICATE THAT IT HAS BEEN DIFFICULT TO

EVEN ACCUMULATE A COUPLE HUNDRETHS OF AN INCH UNDER THE MORE

PRONOUNCED REFLECTIVITIES. WITH THE DECAYING TREND...WILL MAINTAIN

ISOLATED SHOWERS AND SPRINKLES FOR THE COUNTIES BORDERING WI THIS

MORNING.

LITTLE IF ANY APPRECIABLE FORCING WILL REMAIN ACROSS THE AREA THIS

AFTERNOON AND EVENING...SO HAVE LEFT OUT ANY MENTION OF THE PRECIP.

PLENTY OF MID-LEVEL CLOUDS SHOULD LINGER THROUGH THE

AFTERNOON...THOUGH SOME SUN COMBINED WITH RISING 925 TO 850 HPA

TEMPS SHOULD ALLOW FOR TEMPS TO WARM INTO THE LOW 70S ACROSS THE

INTERIOR WEST...AND MID TO UPPER 60S ELSEWHERE FOR THE INTERIOR.

LATE TONIGHT...DEEPER MOISTURE WILL ARRIVE AHEAD OF THE SHORTWAVE

TROUGH LIFTING OUT OF THE CENTRAL PLAINS. WITH INCREASING FORCING

TIED FAIRLY CLOSE TO THE TROUGH...HAVE DECIDED TO KEEP THE ENTIRE

AREA DRY TONIGHT. WITH THAT SAID...SOME MID-LEVEL SHOWER ACTIVITY

MAY PUSH INTO THE WESTERN CWA AFTER MIDNIGHT. THE LOW-LEVEL AIR WILL

STILL BE RELATIVELY DRY...SO SPRINKLES OR A STRAY VERY LIGHT SHOWER

WILL BE POSSIBLE.

.LONG TERM...(THURSDAY THROUGH TUESDAY)

ISSUED AT 505 AM EDT WED MAY 6 2015

AS A PROMINENT RIDGE FROM THE OHIO VALLEY TO NW ONTARIO AND A TROUGH

OVER THE SW CONUS SHIFT TO THE EAST...SW FLOW MID/UPPER LEVEL FLOW

WILL DEVELOP FROM THE SRN PLAINS TO THE WRN GREAT LAKES. WARM

CONDITIONS THU INTO FRI WILL GIVE WAY TO MUCH COOLER WEATHER FROM

THE WEEKEND INTO EARLY NEXT WEEK AS THE MAIN FRONTAL BOUNDARY SHIFTS

TO THE SOUTH OF THE NRN LAKES.

THURSDAY INTO THURSDAY NIGHT...AS THE MID LEVEL RIDGE SHIFTS TO THE

EAST AND A SFC TROUGH ADVANCES INTO CNTRL MN...THE COMBINATION OF

INCREASING MOISTURE/INSTABILITY ALONG WITH THE LIKELIHOOD OF WEAK

SHORTWAVES LIFTING INTO THE AREA FROM THE PLAINS WILL BRING SCT/ISOLD

SHRA/TSRA INTO UPPER MI. THE GREATEST COVERAGE/CHANCES ARE EXPECTED

TO REMAIN OVER THE WEST...CLOSER TO THE STRONGER MID LEVEL SUPPORT

AND INSTABILITY. HIGHS SHOULD CLIMB WELL ABOVE NORMAL WITH HIGHS FROM

THE UPPER 70S TO LOWER 80S...EXCEPT ALONG LAKE MI WHERE READINGS WILL

REMAIN INTO THE UPPER 50S.

FRI...A SURFACE LOW LIFTING TOWARD JAMES BAY WILL DRAG THE COLD

FRONT THROUGH UPPER MI. EXPECT HIGHER SHRA/TSRA CHANCES OVER THE

EAST OF THE CWA...WHEN THE FRONT MOVES INTO THE AREA DURING PEAK

HEATING.

FRI NIGHT INTO SAT...THE ECMWF/GEM WERE MORE AGGRESSIVE IN BRINGING

PCPN BACK THROUGH UPPER MI...AS A SHORTWAVE LIFTS INTO THE WRN LAKES

AND A SFC WAVE DEVELOPS ALONG THE FRONT...COMPARED TO THE GFS WHICH

KEEPS UPPER MI DRY. WHILE CONVECTION CLOSER TO THE FRONT MAY KEEP

THE BOUNDARY FARTHER SOUTH...CANNOT RULE OUT THE GEM/ECMWF TRENDS

WITH AT LEAST CHANCE POPS OVER THE SE HALF FROM FRI NIGHT THROUGH

SATURDAY MORNING.

SUN-TUE...AS THE SW CONUS CLOSED LOW LIFTS THROUGH THE PLAINS...A

LARGE AREA OF PCPN WILL SPREAD TOWARD THE WRN LAKES. UNCERTAINTY

REMAINS WITH THE TIMING AND NRN EXTENT OF THE PCPN...AS THE

GFS/GEFS/GEM WERE MORE SUPPRESSED WITH THE LOW COMPARED TO ECMWF.

REGARDLESS OF THE PCPN AMOUNTS/COVERAGE...MUCH COOLER WEATHER WILL

MOVE IN...ESPECIALLY NORTH WITH STRENGTHENING NE TO N FLOW.

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)

ISSUED AT 738 AM EDT WED MAY 6 2015

A DECAYING LINE OF -SHRA WILL MOVE ACROSS UPPER MI TODAY...BRINGING

MVFR CIGS TO KIWD...AND VFR MID-LEVEL CLOUDS TO KCMX AND KSAW THIS

MORNING. THE CLOUDS SHOULD BREAK UP DURING THE AFTERNOON...BUT A

SURGE OF LOW-LEVEL MOISTURE OFF OF LAKE MI MAY BRING LOW-END MVFR

CIGS TO KSAW OVERNIGHT. ADDITIONALLY...INCREASING LOW-LEVEL WINDS

AHEAD OF A LOW PRESSURE DEVELOPING TO THE WEST WILL RESULT IN A

CHANCE FOR MARGINAL LLWS AT ALL SITES...ESPECIALLY KCMX.

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)

ISSUED AT 428 AM EDT WED MAY 6 2015

BROAD LOW PRESSURE DEVELOPING OVER THE PLAINS WILL BRING SOUTH TO

SOUTHEAST WINDS OF LESS THAN 20 KNOTS THROUGH THURSDAY

NIGHT...THROUGH SOME GUSTS TO 25 KNOTS WILL BE POSSIBLE FOR HIGHER

PLATFORMS THURSDAY AFTERNOON. INCREASING MOISTURE AHEAD OF THIS

SYSTEM WILL ALSO ALLOW FOR AREAS OF FOG AWAY FROM THE UPPER MI

MAINLAND. THE COLD FRONT ASSOCIATED WITH THE LOW WILL CROSS LAKE

SUPERIOR ON FRIDAY...BRINGING NW WINDS OF UP TO 20 KNOTS FRIDAY

NIGHT. AS HIGH PRESSURE SETTLES OVER ONTARIO SATURDAY THROUGH

MONDAY...N TO NE WINDS UNDER 20 KNOTS CAN BE EXPECTED.

.MQT WATCHES/WARNINGS/ADVISORIES...

UPPER MICHIGAN...

NONE.

LAKE SUPERIOR...

NONE.

LAKE MICHIGAN...

NONE.

$$

SHORT TERM...KLUBER

LONG TERM...JLB

AVIATION...KLUBER

MARINE...KLUBER

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